The city flag of San Antonio, Texas was originally drawn by Spanish–American War veteran William W. Herring on May 28, 1933.

The current flag is a slightly modified version of Herring's design, most notably removing the text formerly displayed.

[2] The Alamo illustration represents not only the battle and fort, but the city's role in the entirety of the Texas Revolution.

The idea for a city flag was first brought up to San Antonio commissioners by Arthur J. Storms, a Shriner from Alzafar Temple, on January 18, 1917.

[4][1] Sources differ on when the flag was officially adopted, with American City Flags, a North American Vexillological Association (NAVA) book, listing the adoption date as January 25, 1917,[1] while a 1992 NAVA News publication listed the date as April 3, 1917.

[1] The flag was later presented to the city council on April 18, 1935, by the United War Veterans, and was unofficially adopted on the same day.

This design was slightly modified before being officially approved in 1976,[2] bringing the word "TEXAS" below the star and in the same white block letter font as "SAN ANTONIO".