tarrant_county,_texas | countyseat | fort_worth,_texas <tsp> arlington,_texas | ispartof | tarrant_county,_texas <tsp> arlington,_texas | ispartof | texas <tsp> texas | largestcity | houston <sep> tarrant county is located in the us state of texas as of 2020, it had a population of 2,110,640 it is texas' third-most populous county and the 15th-most populous in the united states its county seat is fort worth 
in texas. the largest city is houston and arlington(part of tarrant county). is part of the state. the county seat of tarrant county in texas is fort worth.tarrant county texas is located in the u.s. state of texas