In March 2020, the Buffalo Bills acquired Stefon Diggs after five successful seasons with the Minnesota Vikings. He was brought in for four draft picks, including a first-round selection. This trade sparked a significant transformation for both Diggs and the franchise, giving quarterback Josh Allen a top-tier receiver and quickly boosting Buffalo’s passing game into one of the most formidable aerial offenses in the league.

Diggs revolutionized elite route-running with precise footwork, quick bursts, and clever double-moves. Excelling at gaining separation early in his routes, he paired dependable, soft hands with intense competitiveness in contested catches. Whether lining up wide or in the slot, Diggs provided Allen with a reliable target capable of winning quick-slant duels under pressure, stretching defenses deep down the sideline, or extending plays after catching the ball.

Before joining the Bills, Diggs's career high was 1,130 receiving yards in a single season. His first season with Buffalo in 2020 surpassed those personal bests dramatically. Building quick rapport with Allen, Diggs led the NFL in receptions (127) and receiving yards (1,535), marking the first time a Bills player achieved the league’s receiving double crown. His outstanding performance earned him his first Pro Bowl and First-Team All-Pro honors, cementing his role as the unquestioned, primary offensive playmaker.

Diggs upheld his elite performance over the next three seasons, leading Buffalo to back-to-back AFC East championships. In 2021, he achieved 103 receptions for 1,225 yards and a career-high 10 receiving touchdowns. He continued to improve in 2022, accumulating 108 catches for 1,429 yards and 11 touchdowns.

He capped off his Bills tenure in 2023 by tallying 107 catches for 1,183 yards and eight touchdowns, securing his fourth consecutive Pro Bowl selection in four years in Buffalo. Across every single season in Western New York, Diggs surpassed 100 receptions and 1,100 receiving yards.

Although Buffalo achieved four consecutive playoff appearances and won division titles, they could not reach the Super Bowl. In April 2024, the Bills traded Diggs to the Houston Texans in a major deal. During his four seasons with the Bills (2020–2023), Diggs played in 65 regular-season games, totaling 449 receptions, 5,372 receiving yards, and 37 touchdowns, leaving a lasting legacy in one of the franchise's most productive offensive periods.