Deputies from Hopkins County and local and state law enforcement officers searched throughout the day for the inmates, who escaped from the jail in Sulphur Springs through a gap between the fence and gate in the recreation yard, the Dallas-Fort Worth area television station WFAA reported.
Officials identified the escapees as Brian Allen Tucker, 45, a capital murder suspect, and John Marlin King, 40, who was being held on suspicion of evading officers.
Both men are considered dangerous.
Deputy Alvin Jordan said jail uniforms were found on nearby railroad tracks.
Tucker last lived in the Dallas suburb of Mesquite, the Dallas Morning News reported.
He and a female accomplice are charged with strangling a 63-year-old man and stealing his musical instruments in May 2011.