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 
arlington is located in tarrant county. texas. the county seat of tarrant county is fort worth. and the largest city in texas is houston.tarrant county texas is located in the u.s. state of texas