Kellen Boswell Winslow was born in St. Louis, Missouri in 1957. He played football for the University of Missouri and was drafted in the first round of the 1979 NFL draft by San Diego Chargers. He played for them until 1987, when he retired from football due to injury. Winslow is frequently credited, along with Ozzie Newsome, with redefining the position of tight end. Historically, tight ends were primarily blockers who also ran short pass routes. Winslow had the size to block and the speed to get downfied quickly along with great athletic ability to both make difficult catches and run well with the ball after the catch. In a 1981 game against the Miami Dolphins, Winslow caught 13 passes and blocked a field goal with seconds remaining to send the game to overtime in one of the greatest single player efforts in Chargers history. After the game Winslow had to be helped, almost carried, from the field. Winslow played in five Pro Bowls and was elected to the Pro Football Hall of Fame in 1995.

Winslow's son, Kellen Winslow II, also plays tight end in the NFL. His college career was at the University of Miami and he was drafted in the first round of the 2004 NFL draft by the Cleveland Browns - ironically the team the Chargers traded with to draft the elder Winslow in 1979.