travis_county,_texas | largestcity | austin,_texas <sep> travis county is located in south central texas as of the 2020 census, the population was 1,290,188 it is the fifth-most populous county in texas its county seat and largest city is austin, the capital of texas the county was established in 1840 and is named in honor of william barret travis, the commander of the republic of texas forces at the battle of the alamo 
austin is the largest city in travis county. texas.its county seat and largest city is austin texas