Do you have to be in college football to be in the NFL?

No ... while it is a rarity, a player can make an NFL roster without having played college ball.

Some of the players in the NFL with no college experience were Michael Lewis who played for 7 seasons and was an All-Pro kick/punt returner in 2002 for the Saints ... Ray Seals who played for 8 seasons and was a starting defensive end for the Steelers in Super Bowl XXX ... Otis Sistrunk who played for 7 seasons and made the 1974 Pro Bowl team and was a starting defensive tackle for the Raiders in Super Bowl XI ... and Herb Mul-Key who played 3 seasons and made the 1973 Pro Bowl as a kick/punt returner for the Redskins.