The Dolphins were founded by attorney-politician Joe Robbie and actor-comedian Danny Thomas. They began play in the AFL in 1966. The region had not had a professional football team since the days of the Miami Seahawks, who played in the All-America Football Conference in 1946, before becoming the first incarnation of the Baltimore Colts. For the first few years, the Dolphins' full-time training camp and practice facilities were at Saint Andrew's School, a private, boys boarding prep school in Boca Raton. Miami joined the NFL as a result of the 1970 AFL–NFL merger.
The team played in its first Super Bowl in Super Bowl VI, losing to the Dallas Cowboys, 24–3. The following year, the Dolphins completed the NFL's only perfect season, culminating in a Super Bowl win, winning all 14 of their regular-season games, and all three of their playoff games, including Super Bowl VII. They were the third NFL team to accomplish a perfect regular season. The next year, the Dolphins won Super Bowl VIII, becoming the first team to appear in three consecutive Super Bowls, and the second team (the first AFL/AFC team) to win back-to-back championships. Miami also appeared in Super Bowl XVII and Super Bowl XIX, losing both games.
For most of their early history, the Dolphins were coached by Don Shula, the most successful head coach in professional football history in terms of total games won. Under Shula, the Dolphins posted losing records in only two of his 26 seasons as the head coach. During the period spanning 1983 to the end of 1999, quarterback Dan Marino became one of the most prolific passers in NFL history, breaking numerous league passing records. Marino led the Dolphins to five division titles, 10 playoff appearances, and an appearance in Super Bowl XIX before retiring following the 1999 season.
In 2008, the Dolphins became the first team in NFL history to win their division and make a playoff appearance following a league-worst 1–15 season. That same season, the Dolphins upset the New England Patriots on the road during Week 3 thanks to the use of the gimmick Wildcat offense, which handed the Patriots their first regular-season loss since December 10, 2006, in which coincidentally, they were also beaten by the Dolphins. To date, 2008 is also the last season the Dolphins won the AFC East.