# EDGAR Filing Document

**Accession Number:** 0001000623
**File Stem:** 0001000623-26-000051
**Filing Date:** 2026-5
**Character Count:** 23949
**Document Hash:** ce0d4c427e2e5fd91a3758a1bbbcd7c9
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001000623-26-000051.hdr.sgml**: 20260507

**ACCESSION NUMBER**: 0001000623-26-000051

**CONFORMED SUBMISSION TYPE**: S-8

**PUBLIC DOCUMENT COUNT**: 15

**REFERENCES 429**: 333-278936

**REFERENCES 429**: 333-287100

**FILED AS OF DATE**: 20260507

**DATE AS OF CHANGE**: 20260507

**EFFECTIVENESS DATE**: 20260507

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Mativ Holdings, Inc.
- **CENTRAL INDEX KEY:** 0001000623
- **STANDARD INDUSTRIAL CLASSIFICATION:** PAPER MILLS [2621]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 621612879
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-8
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-295660
- **FILM NUMBER:** 26954832

**BUSINESS ADDRESS:**
- **STREET 1:** 100 KIMBALL PLACE
- **STREET 2:** SUITE 600
- **CITY:** ALPHARETTA
- **STATE:** GA
- **ZIP:** 30009
- **BUSINESS PHONE:** 8005140186

**MAIL ADDRESS:**
- **STREET 1:** 100 KIMBALL PLACE
- **STREET 2:** SUITE 600
- **CITY:** ALPHARETTA
- **STATE:** GA
- **ZIP:** 30009

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** SCHWEITZER MAUDUIT INTERNATIONAL INC
- **DATE OF NAME CHANGE:** 19950914

**As filed with the Securities and Exchange Commission on May 7, 2026**

**Registration No. 333-_____**

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**WASHINGTON, D.C. 20549**

**FORM S-8**

**REGISTRATION STATEMENT**

***UNDER***

***THE SECURITIES ACT OF 1933***

![image_4.jpg](image_4.jpg)

**MATIV HOLDINGS, INC.**

**(Exact name of registrant as specified in its charter)**

---

| | |
|:---|:---|
| **Delaware** | **62-1612879** |
| **(State or Other Jurisdiction of Incorporation or Organization)** | **(I.R.S. Employer Identification No.)** |

---

**100 Kimball Place, Suite 600**

**Alpharetta, GA 30009**

**(Address and Zip Code of Principal Executive Offices)**

**Mativ Holdings, Inc. 2024 Equity and Incentive Plan (As Amended April 30, 2026)**

**(Full title of the plan)**

**Mark Johnson**

**Chief Legal and Administrative Officer and Corporate Secretary**

**Mativ Holdings, Inc.**

**100 Kimball Place, Suite 600**

**Alpharetta, GA 30009**

**Telephone: 1-770-569-4229**

**(Name, Address, and Telephone Number, including Area Code, of Agent for Service)**

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

---

| | | | |
|:---|:---|:---|:---|
| Large accelerated filer | ☐ | Accelerated filer | ☒ |
| Non-accelerated filer | ☐ | Smaller reporting company | ☐ |
| | | Emerging growth company | ☐ |

---

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

------

**EXPLANATORY NOTE**

This Registration Statement is being filed by Mativ Holdings, Inc. (the "Registrant") for the purpose of registering an additional 1,600,000 shares of Registrant common stock, par value $0.10 per share (the "Common Stock") that were reserved for issuance under the Mativ Holdings, Inc. 2024 Equity and Incentive Plan, as amended (the "Plan"). This Registration Statement on Form S-8 hereby incorporates by reference the contents of the Registrant's prior Registration Statements on Form S-8 filed with the Securities and Exchange Commission (the "Commission") on <u>[April 25, 2024 (SEC File No. 333-278936)](https://www.sec.gov/Archives/edgar/data/1000623/000114036124022116/ef20027638_s8.htm)</u> and <u>[May 8, 2025 (SEC File No. 333-287100)](https://www.sec.gov/Archives/edgar/data/1000623/000100062325000027/mativ-formsx8may2025confor.htm)</u> (the "Prior Registration Statements") registering shares of Common Stock issuable under the Plan. This Registration Statement relates to securities of the same class as those to which the Prior Registration Statements relate and is submitted in accordance with General Instruction E of Form S-8 regarding Registration of Additional Securities. Pursuant to General Instruction E of Form S-8, the contents of the Prior Registration Statements are incorporated herein by reference and made part of this Registration Statement, except for Items 3, 5 and 8, which are being updated by this Registration Statement.

**PART I** 

**INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS** 

All information required by Part I to be contained in the prospectus is omitted from this Registration Statement in accordance with the explanatory note to Part I of Form S-8 and Rule 428 under the Securities Act of 1933, as amended (the "Securities Act"). Documents containing the information required by Part I of the Registration Statement will be sent or given to Plan participants as specified by Rule 428(b)(1) of the Securities Act.

**PART II**

**INFORMATION REQUIRED IN THE REGISTRATION STATEMENT**

---

| | |
|:---|:---|
| **Item 3.** | **Incorporation of Documents by Reference.** |

---

The following documents filed with the Commission by the Registrant are hereby incorporated in this Registration Statement by reference (other than information in such filings deemed, under Commission rules or otherwise, not to have been filed with the Commission):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. The Registrant's Annual Report on <u>[Form 10-K](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000016/matv-20251231.htm)</u> for its fiscal year ended December 31, 2025, filed with the Commission on February 26, 2026;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. The Registrant's Quarterly Report on <u>[Form 10-Q](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000049/matv-20260331.htm)</u> for its quarterly period ended March 31, 2026, filed with the Commission on May 7, 2026;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. The Registrant's Current Reports on Form 8-K, filed with the Commission on <u>[January 14, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000005/matv-20260114.htm)</u>, <u>[February 11, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000009/matv-20260206.htm)</u>, <u>[April 2, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000030/matv-20260330.htm)</u>, <u>[April 6,](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000032/matv-20260403.htm)[2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000032/matv-20260403.htm)</u> and <u>[May](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000043/matv-20260430.htm)[6, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/0001000623/000100062326000043/matv-20260430.htm)</u>;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. All other reports filed by the Registrant pursuant to Sections 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), since the end of the fiscal year covered by the Annual Report; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5. The description of the Common Stock contained in the Registrant's Registration Statement on <u>[Form S-3](https://www.sec.gov/Archives/edgar/data/1000623/000095012309060154/g20959sv3asr.htm)</u> filed with the Commission on November 9, 2009, and any amendments or reports filed for the purposes of updating such description, including <u>[Exhibit 4.3](https://www.sec.gov/Archives/edgar/data/1000623/000100062324000009/ex43descriptionofregistran.htm)</u> to the Registrant's Annual Report on Form 10-K for its fiscal year ended December 31, 2023.

In addition, all documents filed by the Registrant pursuant to Section 13(a), 13(c), 14, and 15(d) of the Exchange Act, subsequent to the date of this Registration Statement (other than information in such filings deemed, under Commission rules or otherwise, not to have been filed with the Commission), prior to the filing of a post-effective amendment to this Registration Statement that indicates that all securities offered have been sold or that deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference in this Registration Statement and to be a part hereof from the date of filing of such documents.

------

Any statement contained in this Registration Statement or in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained or incorporated by reference herein or in any subsequently filed document that is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

---

| | |
|:---|:---|
| **Item 8.** | **Exhibits.** |

---

---

| | |
|:---|:---|
| **Exhibit<br>Number** | **Description** |
| <u>[3.1](https://www.sec.gov/Archives/edgar/data/1000623/000095012309056905/c91817exv3w1.htm)</u> | Certificate of Incorporation of the Registrant filed with the Secretary of State of Delaware on August 21, 1995 (incorporated by reference to Exhibit 3.1 to the Registrant's Form 10-Q for the quarter ended September 30, 2009). |
| <u>[3.2](https://www.sec.gov/Archives/edgar/data/1000623/000119312522188253/d379466dex31.htm)</u> | Certificate of Amendment of the Certificate of Incorporation of the Registrant, effective as of July 6, 2022 (incorporated by reference to Exhibit 3.1 to the Registrant's Current Report on Form 8-K, filed with the Commission on July 6, 2022). |
| <u>[3.3](https://www.sec.gov/Archives/edgar/data/1000623/000119312525052044/d933567dex31.htm)</u> | Amended and Restated Bylaws of the Registrant (incorporated by reference to Exhibit 3.1 to the Registrant's Current Report on Form 8-K, filed with the Commission on March 11, 2025). |
| <u>[4.1](https://www.sec.gov/Archives/edgar/data/1000623/000100062326000043/mativholdingsinc2024equity.htm)</u> | Mativ Holdings, Inc. 2024 Equity and Incentive Plan (As Amended April 30, 2026) (incorporated by reference to Exhibit 10.1 to the Registrant's Current Report on Form 8-K, filed with the Commission on May 6, 2026). |
| <u>[5.1\*](mativ-sx8legalopinionlette.htm)</u> | Opinion of Sidley Austin LLP with respect to validity of issuance of securities. |
| <u>[23.1\*](forms-8consentmay72026.htm)</u> | Consent of Deloitte & Touche LLP. |
| <u>[23.2\*](mativ-sx8legalopinionlette.htm)</u> | Consent of Sidley Austin LLP (included in Exhibit 5.1). |
| <u>[24.1\*](#i47af65776c864f2c9ee1a58d1233e84c_7)</u> | Power of Attorney (included on the signature pages to the Registration Statement and incorporated herein by reference). |
| <u>[107\*](exfilingfeesmay2026.htm)</u> | Filing Fee Table. |

---

\* Filed herewith.

------

**SIGNATURES**

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Alpharetta, State of Georgia, on May 7, 2026.

---

| | |
|:---|:---|
| MATIV HOLDINGS, INC. | MATIV HOLDINGS, INC. |
| By: | /s/ Mark Johnson |
| Name: | Mark Johnson |
| Title: | Chief Legal and Administrative Officer and Corporate Secretary |

---

------

**POWER OF ATTORNEY**

We, the undersigned officers and directors of Mativ Holdings, Inc., hereby severally constitute and appoint Shruti Singhal, Scott Minder and Mark Johnson, our true and lawful attorneys with full power to them, and each of them singly, to sign for us and in our names in the capacities indicated below, the Registration Statement on Form S-8 filed herewith and any and all subsequent amendments to said Registration Statement, and generally to do all such things in our names and on our behalf in our capacities as officers and directors to enable Mativ Holdings, Inc. to comply with the provisions of the Securities Act of 1933, as amended, and all requirements of the Securities and Exchange Commission, hereby ratifying and confirming our signatures as they may be signed by our said attorneys, or any of them, to said Registration Statement and any and all amendments thereto.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

---

| | | |
|:---|:---|:---|
| **Signature** | **Title** | **Date** |
| /s/ Shruti Singhal | President and Chief Executive Officer and Director<br>*(Principal Executive Officer)* | May 7, 2026 |
| Shruti Singhal | President and Chief Executive Officer and Director<br>*(Principal Executive Officer)* | May 7, 2026 |
| /s/ Scott Minder | Chief Financial Officer<br>*(Principal Financial Officer)* | May 7, 2026 |
| Scott Minder | Chief Financial Officer<br>*(Principal Financial Officer)* | May 7, 2026 |
| /s/ Cheryl Allegri | Corporate Controller and Chief Accounting Officer<br>*(Principal Accounting Officer)* | May 7, 2026 |
| Cheryl Allegri | Corporate Controller and Chief Accounting Officer<br>*(Principal Accounting Officer)* | May 7, 2026 |
| /s/ Deborah Borg | Director | May 7, 2026 |
| Deborah Borg | Director | May 7, 2026 |
| /s/ William M. Cook | Director | May 7, 2026 |
| William M. Cook | Director | May 7, 2026 |
| /s/ Marco Levi | Director | May 7, 2026 |
| Marco Levi | Director | May 7, 2026 |
| /s/ Kimberly Ritrievi | Director | May 7, 2026 |
| Kimberly Ritrievi | Director | May 7, 2026 |
| /s/ John Stipancich | Director | May 7, 2026 |
| John Stipancich | Director | May 7, 2026 |

---

## Ex-Filing

?xml version='1.0' encoding='ASCII'? EX-FILING FEES

---

| |
|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Calculation of Filing Fee Tables**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **S-8**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Mativ Holdings, Inc.**  |

---

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Type**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Class Title**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Calculation Rule**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Amount Registered**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Proposed Maximum Offering Price Per Unit**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Maximum Aggregate Offering Price**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Rate**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Amount of Registration Fee**  |
| 1 | Equity | Common Stock, par value $0.10 per share | Other | 1600000 | $8.83 | $14128000.00 | 0.0001381 | $1951.08 |
| Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: | Total Offering Amounts: |  | $14128000.00  |  | $1951.08  |
| Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  | Total Fee Offsets:  |  |  |  | $0.00  |
| Net Fee Due:  | Net Fee Due:  | Net Fee Due:  | Net Fee Due:  | Net Fee Due:  |  |  |  | $1951.08  |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Offering Note** <br>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>1</sup> (a) Mativ Holdings, Inc., a Delaware corporation (the Registrant), is registering an additional 1,600,000 shares of common stock, par value $0.10 per share (the Common Stock), that may be issued under the Mativ Holdings, Inc. 2024 Equity and Incentive Plan, as amended (the Plan). Pursuant to Rule 416 of the Securities Act of 1933, as amended (the Securities Act), this Registration Statement also covers such additional and indeterminate number of securities as may become issuable pursuant to the provisions of the Plan relating to adjustments for changes resulting from a stock dividend, stock split or similar change. (b) The offering price per unit and in the aggregate are estimated in accordance with Rule 457(h) under the Securities Act solely for the purpose of calculating the registration fee. The price of $8.83 per share represents the average high and low sales prices of the Common Stock as quoted on the New York Stock Exchange on May 4, 2026.

---

| |
|:---|
| |
| **Rule 457(p)** |
| Fee Offset Claims |
| Fee Offset Sources |

---

## Exhibit 5.1

---

| | | |
|:---|:---|:---|
| ![sidleyphotoa.jpg](sidleyphotoa.jpg) | SIDLEY AUSTIN LLP<br>ONE SOUTH DEARBORN STREET<br>CHICAGO, IL 60603<br>+1 312 853 7000<br>+1 312 853 7036 FAX<br>AMERICA ASIA PACIFIC EUROPE | **Exhibit 5.1** |

---

May 7, 2026

Mativ Holdings, Inc.

100 Kimball Place, Suite 600

Alpharetta, GA 30009

Re: <u>1,600,000 shares of Common Stock, $0.10 par value per share</u>

Ladies and Gentlemen:

We refer to the Registration Statement on Form S-8 (the "<u>Registration Statement</u>") being filed by Mativ Holdings, Inc., a Delaware corporation (the "<u>Company</u>"), with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the "<u>Securities Act</u>"), relating to the registration of 1,600,000 shares of common stock, $0.10 par value per share (the "<u>Common Stock</u>"), of the Company which may be issued under the Mativ Holdings, Inc. 2024 Equity and Incentive Plan, as amended (the "<u>Plan,</u>" and the aggregate shares of Common Stock to be registered under the Registration Statement, the "<u>Registered Shares</u>").

This opinion letter is being delivered in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act.

We have examined the Registration Statement, the Company's Certificate of Incorporation, the Certificate of Amendment of the Certificate of Incorporation of the Company, the Company's Amended and Restated Bylaws, the Plan, the resolutions adopted by the board of directors of the Company relating to the Registration Statement and the Plan, and the proposal adopted by the stockholders of the Company relating to the Plan. We have also examined originals, or copies of originals certified to our satisfaction, of such agreements, documents, certificates and statements of the Company and other corporate documents and instruments, and have examined such questions of law, as we have considered relevant and necessary as a basis for this opinion letter. We have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures, the legal capacity of all persons and the conformity with the original documents of any copies thereof submitted to us for examination. As to facts relevant to the opinions expressed herein, we have relied without independent investigation or verification upon, and assumed the accuracy and completeness of, certificates, letters and oral and written statements and representations of public officials and officers and other representatives of the Company.

Sidley Austin LLP is a limited liability partnership practicing in affiliation with other Sidley Austin partnerships.

------

![sidleyphotoa.jpg](sidleyphotoa.jpg)

Mativ Holdings, Inc.

May 7, 2026

Based on the foregoing, we are of the opinion that each Registered Share that is newly issued pursuant to the Plan will be validly issued, fully paid and non-assessable when: (i) the Registration Statement, as finally amended, shall have become effective under the Securities Act; (ii) such Registered Share shall have been duly issued and delivered in accordance with the Plan; and (iii) a certificate representing such Registered Share shall have been duly executed, countersigned and registered and duly delivered to the person entitled thereto against payment of the agreed consideration therefor (in an amount not less than the par value thereof) or, if any such Registered Share is to be issued in uncertificated form, the Company's books shall reflect the issuance of such Registered Share to the person entitled thereto against payment of the agreed consideration therefor (in an amount not less than the par value thereof), all in accordance with the Plan.

This opinion letter is limited to the General Corporation Law of the State of Delaware. We express no opinion as to the laws, rules or regulations of any other jurisdiction, including, without limitation, the federal laws of the United States of America or any state securities or blue sky laws.

We hereby consent to the filing of this opinion letter as an exhibit to the Registration Statement and to all references to our Firm included in or made a part of the Registration Statement. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act.

Very truly yours,

/s/ Sidley Austin LLP

Sidley Austin LLP

## Exhibit 23.1

**Exhibit 23.1**

**CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM**&nbsp;&nbsp;&nbsp;&nbsp;

We consent to the incorporation by reference in this Registration Statement on Form S-8 of our reports dated February 26, 2026, relating to the financial statements of Mativ Holdings, Inc. and subsidiaries ("the Company") and the effectiveness of the Company's internal control over financial reporting, appearing in the Annual Report on Form 10-K of the Company for the year ended December 31, 2025.

/s/ Deloitte & Touche LLP

Atlanta, GA

May 7, 2026

<br>