UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549



FORM 10-K/A

(Amendment No. 1)



(Mark one)



x           ANNUAL
REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934



For the fiscal year ended December 31,
2015



 ̈           TRANSITION
REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934



For the transition period from ________ to ________



Commission file number 0-5576



SPHERIX INCORPORATED

(Exact name of Registrant as specified in its
Charter)



|Delaware                                                       |                                                                     | 52-0849320                          
|-------------------------------------------------------------- | ------------------------------------------------------------------- | ------------------------------------
|(State or other jurisdiction of incorporation or organization) |                                                                     | (I.R.S. Employer Identification No.)
|                                                               |                                                                     |                                     
|                                                               | 1350 Ave of the Americas;
        2nd FL
        New York, NY 10019 |                                     
|                                                               | (Address of principal executive
 offices)                           |                                     



Registrant’s telephone number, including
area code:  (703) 992-9260

Securities registered pursuant to Section 12(b)
of the Act:



|Title of each class                        |  | Name of each exchange on which registered
|------------------------------------------ |  | -----------------------------------------
|Common Stock ($0.0001 par value per share) |  | The NASDAQ Capital Market                



Securities registered pursuant to Section 12(g) of the Act:  None.



Indicate by check mark if the registrant is
a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.  Yes  ̈
No x



Indicate by check mark if the registrant is
not required to file reports pursuant to Section 13 or Section 15(d) of the Act.  Yes  ̈
No x



Indicate by check mark whether the Registrant (1) has filed
all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months
(or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.  Yes x No  ̈



Indicate by check mark whether the registrant
has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted
and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant
was required to submit and post such files).  Yes x No  ̈



Indicate by check mark if disclosure of delinquent
filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of Registrant’s
knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment
to this Form 10-K.  ̈



Indicate by check mark whether the Registrant
is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company (as defined in Rule
12b-2 of the Exchange Act).



Large Accelerated Filer  ̈
Accelerated Filer  ̈ Non-accelerated Filer  ̈
Smaller Reporting Company x



Indicate by check mark whether the Registrant
is a shell company (as defined in Rule 12b-2 of the Exchange Act).  Yes  ̈
No x



The aggregate market value of the voting stock
held by non-affiliates of the registrant as of the last business day of the registrant’s most recently completed second fiscal
quarter ended June 30, 2015: $16,138,853 based upon the closing sale price of our common stock of $9.12 (giving effect to a 1-for-19
reverse stock split effected by the registrant on March 4, 2016) on that date. Common stock held by each officer and director and
by each person known to own in excess of 5% of outstanding shares of our common stock has been excluded in that such persons may
be deemed to be affiliates.  The determination of affiliate status in not necessarily a conclusive determination for other
purposes.



There were 2,946,978 shares of the Registrant’s
Common Stock outstanding as of March 25, 2016.
















EXPLANATORY NOTE



We are filing this Amendment No. 1 on Form 10-K/A (“Amendment
No. 1”) to our Annual Report on Form 10-K for the fiscal year ended December 31, 2015, as originally filed with the Securities
and Exchange Commission (the “SEC”) on March 29, 2016 (the “Original Filing”), for the purpose of amending
a reference to the incorrect date for the agreed upon Standstill Period under the Patent License Agreement entered into with RPX
Corporation described in Item 1of Part I. The Original Filing stated that the Standstill Period was until May 23, 2015; the correct
date is May 23, 2016.



Except for the foregoing, this Amendment No. 1 does not update or
modify any of the information contained in the Original Filing. Other than as specifically set forth herein, this Amendment No.
1 continues to speak as of the date of the Original Filing and we have not updated or amended the disclosures contained therein
to reflect events that have occurred since the date of the Original Filing.  Information not affected by this Amendment
No. 1 remains unchanged and reflects the disclosures made at the time of the Original Filing. Accordingly, this Amendment No. 1
should be read in conjunction with our filings made with the SEC subsequent to the date of the Original Filing.



SPECIAL CAUTIONARY NOTICE REGARDING FORWARD
LOOKING STATEMENTS



This Amendment No. 1 contains “forward looking statements”
within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934.  Forward
looking statements are often identified by the words “will,” “may,” “believes,” “estimates,”
“expects,” “intends,” “plans,” “projects” and words of similar import.  Such
words and expressions are intended to identify such forward looking statements, but are not intended to constitute the exclusive
means of identifying such statements.  Such forward looking statements involve known and unknown risks, uncertainties
and other factors, including those described in “Risk Factors” in Item 1A of the Original Filing that may cause our
actual results, performance or achievements, or industry results, to be materially different from any future results, performance
or achievements expressed or implied by such forward looking statements.  Given these uncertainties, prospective investors
are cautioned not to place undue reliance on such forward looking statements.



All references in this Amendment No. 1 to “we,” “us,”
“our” and the “Company” refer to Spherix Incorporated, a Delaware corporation and its consolidated subsidiaries
unless the context requires otherwise.



PART IV



Item 15.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES



The exhibits listed in the Exhibit Index of the Original Filing
are incorporated by reference into this Amendment No. 1, and the exhibits listed in the Exhibit Index to this Amendment No. 1 are
filed herewith.











SIGNATURES



Pursuant to the requirements of Section 13
or 15(d) of the Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned,
thereunto duly authorized.



|                     | Spherix Incorporated (Registrant)                                           
|-------------------- | ----------------------------------------------------------------------------
|                     |                                                                             
|Date:  April 1, 2016 | By:  /s/ Anthony Hayes                                                      
|                     | Anthony Hayes                                                               
|                     | Director and Chief Executive Officer (Principal Executive Officer)          
|                     |                                                                             
|Date:  April 1, 2016 | By:  /s/ Frank Reiner                                                       
|                     | Frank Reiner                                                                
|                     | Interim Chief Financial Officer (Principal Financial and Accounting Officer)











EXHIBIT INDEX



|Exhibit No. | Description                                                                                                               
|----------- | --------------------------------------------------------------------------------------------------------------------------
|            |                                                                                                                           
|31.1        | Certification of Chief Executive Officer of Spherix Incorporated pursuant to Section 302 of the Sarbanes-Oxley Act of 2002
|            |                                                                                                                           
|31.2        | Certification of Chief Financial Officer of Spherix Incorporated pursuant to Section 302 of the Sarbanes-Oxley Act of 2002
|            |                                                                                                                           
|32.1        | Certification of Chief Executive Officer of Spherix Incorporated pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
|            |                                                                                                                           
|32.2        | Certification of Chief Financial Officer of Spherix Incorporated pursuant to Section 906 of the Sarbanes-Oxley Act of 2002