Selected in the fifth round (42nd overall) of the 1944 NFL Draft out of UCLA—where he led the Bruins to their first Rose Bowl appearance—Bob Waterfield stepped into professional football and delivered one of the most remarkable rookie campaigns in gridiron history. Debuting for the Cleveland Rams in 1945, the multi-talented phenom led the league with 14 touchdown passes while guiding the franchise to a 9–1 record and a 15–14 victory over the Washington Redskins in the NFL Championship Game. For his extraordinary debut, Waterfield was named NFL Most Valuable Player, becoming the first rookie in league history to capture the award.

Waterfield was the quintessential triple-threat star of pro football's single-wing transition era, influencing games on offense, defense, and special teams. Beyond his aerial distribution at quarterback, he served as the team's primary placekicker and punter, leading the league in field goals twice and average punting yards in 1948. On defense, his ball-hawking instincts at defensive back produced 20 career interceptions across eight seasons, showcasing an all-around athletic versatility modern football rarely sees.

After their 1945 title, the Rams relocated west to become the Los Angeles Rams in 1946, and Waterfield quickly became a Southern California sports icon. He picked up right where he left off in his new home, finishing second in passing yards (1,747) and throwing a league-high 17 touchdown passes while earning his second consecutive First-Team AP All-Pro selection. Off the field, his star power burned just as brightly when he married Hollywood superstar Jane Russell, turning the couple into one of Los Angeles's original glamour pairings.

While his statistical efficiency fluctuated in subsequent campaigns, Waterfield regained top form in 1949 to earn his third First-Team AP All-Pro selection after leading the NFL with 1,608 passing yards and 23 touchdown passes. He remained at the top of his game as the league entered the 1950s, earning selections to the first two Pro Bowls in 1950 and 1951. His steady leadership in the pocket helped propel Los Angeles to three straight NFL Championship Game appearances from 1949 through 1951.

The peak of the Rams' Southern California revival arrived in 1951, when Waterfield anchored a high-powered offense that captured the NFL Championship with a 24–17 victory over the Cleveland Browns. Managing the offense alongside head coach Joe Stydahar, Waterfield shared signal-calling duties with fellow future Hall of Famer Norm Van Brocklin, creating a lethal two-quarterback system that confounded opposing defensive coordinators and produced one of the most prolific passing attacks of the mid-century era.

Waterfield played one final season in 1952, splitting snaps with Van Brocklin before retiring at age 32 to transition into film production and coaching. He later returned to the franchise as head coach of the Los Angeles Rams from 1960 to 1962. In 1952, the Rams honored his foundational contributions by officially retiring his #7 jersey, ensuring no future Ram would wear his iconic number.

His legacy as one of football's greatest pioneers was permanently sealed in 1965 when he was enshrined in the Pro Football Hall of Fame in Canton, Ohio. 

With the Rams, he threw for 814 completions on 1,617 attempts, 11,849 passing yards, and 97 touchdown passes, plus 60 field goals, 315 extra points, and 20 defensive interceptions.