Lyda Ann Thomas (1936/1937 – April 19, 2017) was an American politician. She served as the mayor of Galveston, Texas from 2004 to 2010. She was first elected in 2004 to replace Roger "Bo" Quiroga. Thomas was the third female mayor of Galveston. She serve three terms as mayor, and stepped down in 2010 after reaching her a city-imposed term-limit. She was a member of the Democratic Party.