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Table of Contents ☑ ☐ UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 Form 10 - K ( Mark One ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 or TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period From Texas to Commission file number 000-12247 SOUTHSIDE BANCSHARES , INC . ( State or Other Jurisdiction of Incorporation or Organization ) 1201 S. Beckham Avenue , Tyler , Texas ( Address of Principal Executive Offices ) Title of each class Common Stock , $ 1.25 par value ( Exact name of registrant as specified in its charter ) Registrant's telephone number , including area code : ( 903 ) 531-7111 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol SBSI 75-1848732 ( I.R.S. Employer Identification No. ) 75701 ( Zip Code ) Name of each exchange on which registered NASDAQ Global Select 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 ☐ 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 ☑ 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 ☑ No ☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( § 232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes ☑ No ☐ Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or emerging growth company . See the 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 Non - accelerated filer ☑ ☐ 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 13 ( a ) of the Exchange Act . ☐ ㅁㅁㅁ Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . ☑ Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes No ☑ The aggregate market value of the common stock held by non - affiliates of the registrant as of June 30 , 2020 , was approximately $ 860.5 million ( based upon the closing price of $ 27.72 per share as reported by the NASDAQ Global Select Market on June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter ) . As of February 23 , 2021 , there were 32,757,551 shares of the registrant's common stock outstanding . DOCUMENTS INCORPORATED BY REFERENCE Certain portions of the Registrant's Proxy statement to be filed for the Annual Meeting of Shareholders to be held May 12 , 2021 are incorporated by reference into Part III of this Annual Report on Form 10 - K . Other than those portions of the proxy statement specifically incorporated by reference pursuant to Items 10-14 of Part III hereof , no other portions of the proxy statement shall be deemed so incorporated .