Selected in the seventh round of the 1958 NFL Draft out of Illinois, Bobby Mitchell became another iconic discovery by head coach Paul Brown. Boasting electric 9.5-second 100-yard-dash speed, Mitchell immediately stepped into the Cleveland backfield alongside Jim Brown, creating one of the most explosive, dynamic rushing duos in football history.

Cleveland utilized Mitchell as a versatile and multifaceted player. Capable of scoring at any moment he possessed the ball, he positioned himself at halfback, extended out wide as a pass receiver, and served as the team's primary kick and punt return specialist. During his four seasons in Ohio, Mitchell accumulated an impressive total of 5,916 all-purpose yards, consistently ranking within the top six league-wide in all-purpose yards each season. His exceptional speed on the periphery complemented Jim Brown's formidable interior power, propelling the Browns' offense to consecutive winning seasons and securing a place in the 1957 NFL Championship Game.

Despite his significant productivity and popularity, Mitchell was traded after the 1961 season. In pursuit of a formidable full-time fullback to complement Jim Brown, Cleveland exchanged Mitchell to Washington for the rights to Heisman Trophy recipient Ernie Davis. Tragically, Davis was diagnosed with leukemia shortly after the trade, which prevented him from ever participating in an NFL game. Concurrently, the transaction bore substantial historical significance: Washington was the last remaining segregated team in the NFL, and owner George Preston Marshall faced substantial pressure from the federal government to desegregate. Mitchell thus became the first African American star in the history of the Washington franchise.

Switching to a full-time flanker in his new environment, Mitchell achieved a Hall of Fame level, leading the league in receiving yards twice and earning four Pro Bowl selections. Over four seasons with Cleveland (1958–1961), he played 48 games, totaling 2,297 rushing yards, 1,462 receiving yards, and 38 touchdowns.