Drafted 14th overall in the renowned 1983 NFL Draft class originating from Miami, Jim Kelly initially expressed reluctance regarding the prospect of playing in Western New York, choosing instead to sign with the Houston Gamblers of the USFL. After two outstanding seasons within the spring league, the USFL ceased operations, prompting Kelly to relocate northward and join Buffalo in 1986. What commenced as a hesitant arrival ultimately evolved into one of the most celebrated bonds between a player and a city in sports history, as Kelly wholeheartedly adopted the blue-collar ethos of the region and became the cherished face of the franchise.

Kelly epitomized a formidable, physically robust pocket passer, embodying a linebacker’s mentality in the quarterback role. Serving as the field general for the innovative "K-Gun" offense, he exercised comprehensive control at the line of scrimmage, calling plays without a huddle to prevent opposing defenses from mounting effective countermeasures. Kelly demonstrated a rapid release, superior intermediate ball placement, and exceptional composure under pressure, consistently remaining upright in the pocket to deliver accurate throws just prior to receiving substantial hits.

Kelly made an immediate impact when he debuted with the Bills in 1986, passing for 3,593 yards and 22 touchdowns. He earned his first Pro Bowl in 1987 after guiding Buffalo to a .500 record, and secured another in 1988 as he led the team to a 12–4 record and an AFC East championship.

His prime years aligned with Buffalo's remarkable streak of four straight AFC championships from 1990 to 1993. In 1990, Kelly topped the NFL in passer rating (101.2) and completion percentage (63.3%) while leading the team to Super Bowl XXV. The following year, he delivered an outstanding 1991 season, earning First-Team All-Pro honors, leading the league with 33 touchdown passes, and setting a personal best with 3,844 passing yards. He earned Pro Bowl selections in 1990, 1991, and 1992, and was among the top five in MVP voting in 1990 and 1991.

Over his 11 seasons in Buffalo, Kelly led the team to six AFC East division titles and eight playoff appearances. He retired following the 1996 season holding every major franchise passing record, finishing his career with 35,467 passing yards and 237 touchdown passes across 160 regular-season starts.

In November 2001, the organization honored his legacy by inducting him into the Buffalo Bills Wall of Fame and retiring his No. 12 jersey, the first in team history to do so. The next year, Kelly was elected to the Pro Football Hall of Fame in his first year of eligibility.