The Buffalo Bills are a professional American football team based in the Buffalo, New York metropolitan area, and play their home games in the suburb of Orchard Park. They currently belong to the Eastern Division of the American Football Conference (AFC) in the National Football League (NFL). The Bills began play in 1960 as a charter member of the American Football League and joined the NFL as part of the AFL-NFL Merger.

The Bills won two consecutive AFL titles in 1964 and 1965. The club is also the first team to appear in four consecutive Super Bowls, losing all of them. The franchise name comes from the legendary western hunter and performer Buffalo Bill.

The Buffalo Bills were a charter member of the American Football League in 1960. After a public contest, the team adopted the same name as the former All-America Football Conference team in Buffalo. In the AFL, a predominantly offensive league, the Bills were a great defensive team.

The 1964 Bills allowed just 913 yards rushing on 300 attempts during the regular season, a pro football record. The same defense registered fifty quarterback sacks, a team record that stands today, even though it was established in a 14-game season. They were the first American Football League team to win 13 games in a season. The 1964 defense also allowed only four touchdowns rushing all season, and started a string that would extend into the 1965 season: seventeen straight games without allowing an opponent to score a rushing touchdown. Eight members of the 1964 squad were on that year's AFL Eastern Division All-Star Team, including cornerback Butch Byrd. Three were eventually named to the American Football League's All-Time Team, and six to the second team. The only professional football player ever inducted to the Pro Football Hall of Fame, without ever playing in the NFL, was a member of the 1964 Bills; guard Billy Shaw.

The Bills won AFL championships in both 1964 and 1965, were one of only three teams to appear in an AFL championship game for three consecutive years, and the only AFL team to play in the post-season for four straight years, 1963 through 1966. In addition to their defensive prowess, the Bills had offensive muscle as well, in stars such as fullback Cookie Gilchrist, quarterbacks Jack Kemp and Daryle Lamonica, and receivers Elbert Dubenion and Ernie Warlick. Tragedy struck the Bills when Bob Kalsu, an offensive lineman, quit the team after his 1968 rookie season to serve in the Vietnam War, where he was killed in action in 1970.

Before the 1969 season, the Bills drafted running back O.J. Simpson, who would become the face of the franchise through the 1970s. The Bills became part of the NFL when the latter absorbed the AFL in a merger in 1970. In 1971, not only did the Bills finish in sole possession of the NFL's worst overall record at 1–13, but they also scored the fewest points (184) in the league that year while allowing the most (394); no NFL team has since done all three of those things in the same season in a non-strike year. Lou Saban, who had coached the Bills' AFL championship teams, was re-hired in 1972.

1973 was a season of change: Joe Ferguson became their new quarterback, they moved into a new stadium, Simpson recorded a 2,000-yard season and was voted NFL MVP, and the team had its first winning record since 1966. The "Electric Company" of Simpson, Jim Braxton, Paul Seymour, Joe DeLamielleure as recounted in the locally-recorded hit "Turn on the Juice", lead a dramatic turnaround on the field. The team made the NFL playoffs for the first time in 1974, but lost in the first round to the eventual Super Bowl champion Pittsburgh Steelers.

After a mediocre 1975 season the Bills had internal troubles in 1976, as the team dropped to the bottom of the AFC East, where they stayed for the rest of the 1970s. After the 1977 season Simpson was traded to the San Francisco 49ers. Chuck Knox was hired as head coach and he would end up leading the Bills back to the top.

1980 marked another breakthrough for the Bills. They beat the archrival Miami Dolphins for the first time in 11 years in their season opener, en route to winning their first AFC East title. The following season they lost their title to the Dolphins, but won their first NFL playoff game (over the New York Jets). They lost in the second round to the eventual AFC champion Cincinnati Bengals. The following year—the strike-shortened season of 1982—the Bills slipped to a 4–5 final record.

In the famous 1983 draft the Bills selected quarterback Jim Kelly as their replacement to an aging Joe Ferguson, but Kelly decided to play in the upstart United States Football League instead. Knox left his coaching position to take a job with the Seattle Seahawks, and new coach Kay Stephenson proved to be less than stellar. In 1984 and 1985 the Bills went 2–14.