# EDGAR Filing Document

**Accession Number:** 0001262823
**File Stem:** 0001193125-26-138977
**Filing Date:** 2026-4
**Character Count:** 4575
**Document Hash:** e4f77dfe9651c1d101f693601ab36b06
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-138977.hdr.sgml**: 20260402

**ACCESSION NUMBER**: 0001193125-26-138977

**CONFORMED SUBMISSION TYPE**: DEFA14A

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20260402

**DATE AS OF CHANGE**: 20260402

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** WESTLAKE CORP
- **CENTRAL INDEX KEY:** 0001262823
- **STANDARD INDUSTRIAL CLASSIFICATION:** INDUSTRIAL ORGANIC CHEMICALS [2860]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 760346924
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** DEFA14A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-32260
- **FILM NUMBER:** 26830634

**BUSINESS ADDRESS:**
- **STREET 1:** 2801 POST OAK BLVD
- **STREET 2:** SUITE 600
- **CITY:** HOUSTON
- **STATE:** TX
- **ZIP:** 77056
- **BUSINESS PHONE:** 713-960-9111

**MAIL ADDRESS:**
- **STREET 1:** 2801 POST OAK BLVD
- **STREET 2:** SUITE 600
- **CITY:** HOUSTON
- **STATE:** TX
- **ZIP:** 77056

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** WESTLAKE CHEMICAL CORP
- **DATE OF NAME CHANGE:** 20030908

##### [**Table of Contents**](#toc)
**UNITED STATES** 

**SECURITIES AND EXCHANGE COMMISSION** 

**Washington, D.C. 20549** 

**SCHEDULE 14A** 

**Proxy Statement Pursuant to Section 14(a) of the** 

**Securities Exchange Act of 1934** 

**(Amendment No.)** 

Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ **Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))**

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material under §240.14a-12

## WESTLAKE CORPORATION
**(Name of Registrant as Specified In Its Charter)** 

**(Name of Person(s) Filing Proxy Statement, if other than the Registrant)** 

Payment of Filing Fee (Check all boxes that apply):

☒ No fee required

☐ Fee paid previously with preliminary materials

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

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##### [**Table of Contents**](#toc)
![LOGO](g49581g83u46.jpg)

Your Vote Counts! WESTLAKE CORPORATION 2026 Annual Meeting Vote by May 13, 2026 11:59 PM ET WESTLAKE CORPORATION ATTN: GENERAL COUNSEL 2801 POST OAK BLVD, SUITE 600 HOUSTON, TX 77056 V87486-P47409 You invested in WESTLAKE CORPORATION and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the stockholder meeting to be held on May 14, 2026. Get informed before you vote View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 30, 2026. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. For complete information and to vote, visit www.ProxyVote.com Control # Smartphone users Vote in Person at the Meeting\* Point your camera here and May 14, 2026 9:00 AM CDT vote without entering a control number Westlake Center 2801 Post Oak Boulevard Houston, TX 77056 USA \*Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares.

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##### [**Table of Contents**](#toc)
![LOGO](g49581g99e73.jpg)

Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. Board Voting Items Recommends 1. Election of Class I Directors: Nominees: 01) Catherine T. Chao For 02) Roger A. Cregg 03) Jean-Marc Gilson 04) Kimberly S. Lubel 05) Jeffrey W. Sheets 2. An advisory vote to approve named executive officer compensation. For 3. To ratify the appointment of PricewaterhouseCoopers LLP to serve as our independent registered public accounting For firm for the fiscal year ending December 31, 2026. NOTE: To act upon any other matters that may properly come before the Annual Meeting. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Delivery Settings". V87487-P47409