Langer was the anchor of the Miami offensive line during the Dolphins' championship years of the 1970s. Coming out of South Dakota State in 1970, he was signed as a free agent by Cleveland but was relieased on the final cut. Langer was picked up on waivers by the Dolphins and , after spending most of the year on the taxi squad, played in the fianl five games of 1970, mainly on special teams. After serving as a backup at center the following season, in 1972 he won the starting job, which he would hold until sidelined with a knee injury in 1979. A consensus All-Pro from 1973-77, Langer was a six-time Pro Bowl selection (five times as a starter). He played in a club-high 128 straight games during his career and also had a team-record 109 consecutive starts. Voted the team's Most Valuable Player by South Florida media in 1975.

Langer also holds the distinciton of having played every offensive down in the Dolphins' perfect 1972 season. Wanting to spend the final years of his career near his Royalton, Minnesota home, at his own request Langer was traded to the Minnesota Vikings in 1980, where he played for two seasons (1980-81). He was elected to the Hall of Fame in his first year of eligibility. In addition, on November 19, 1990, he was enshrined on the Dolphin Honor Roll at Joe Robbie Stadium.