Warfield graduated from Warren G. Harding High School in Warren, Ohio in 1960. He was a star running back and defensive back for the Panthers, joining the varsity as a sophomore in 1957. In 1958, Warfield ran for 810 yards and scored 15 touchdowns—a campaign highlighted by a 6-0 victory over the powerhouse Massillon Tigers. Warfield ran for 1158 yards in 1959 and hit the paydirt 13 times. Warfield also set a state mark in the long jump.
Shortly before Super Bowl VI President Richard M. Nixon famously telephoned Dolphins coach Don Shula to suggest that they run a particular pass play to Warfield. The play, a down-and-in pattern, was tried and resulted in an incomplete pass.
In 1974, shortly after the Dolphins' won Super Bowl VIII, Warfield and teammates Larry Csonka and Jim Kiick made what were then surprising decisions. They left the Dolphins at the conclusion of the season for what appeared to be more lucrative pastures with the Toronto Northmen of World Football League. (The Northmen moved to Memphis without playing a game in Toronto, and became the Memphis Southmen.) Warfield played the 1975 season with the Memphis Southmen, before finishing his playing career with the Browns in 1976 and 1977. He was in the Pro Bowl eight times, and was named All League six times.
In his 13 NFL seasons Warfield caught 427 passes for 8,565 yards for 20.1 yards per catch, 9th highest all time, and scored 85 touchdowns. He added another 204 yards on 22 rushing attempts. In his only WFL season (1975) he caught 25 passes for 422 yards, a 16.9 yards per catch average, with 3 touchdowns.
In his rookie season 1964, he caught 52 receptions (his best season for receptions) for 920 yards and 9 touchdowns as the Browns won the NFL Championship.
In 1968 he caught 50 passes and for the only time in his career gained over 1,000 yards in receiving (1,067 yards). That year he scored 12 touchdowns as the Browns reached the NFL Championship for the third time in the 1960s.
For most of Warfield's tenure in Miami the Dolphins ran an offense which stressed running the ball. Warfield was considered a major threat on any given play. Even though he only caught 29 passes during the 1973 NFL season, 11 of those receptions were touchdowns, with four coming in the first half of the regular season finale. Three years earlier, when he arrived in Miami, he caught only 28 passes but he averaged 25.1 yards per catch.
In 2013 Warren G. Harding High School had a life size statue made of Paul Warfield.
He was inducted into the Pro Football Hall of Fame in 1983. In 1999, he was ranked number 60 on The Sporting News' list of the 100 Greatest Football Players. In 1979 Ohio State inducted him into its Varsity O Hall of Fame for both his football and track accomplishments.
Warfield had the honor of performing the coin flip at the Ohio State-Michigan game in 2006, in which the then #1 ranked Buckeyes beat the #2 ranked Wolverines 42-39 in Columbus, Ohio. He has worked as a special assignment scout for the Browns. He currently is retired and living in Rancho Mirage, CA.