Lyons attended the University of Alabama, where he played for coach Bear Bryant's Alabama Crimson Tide football team from 1975 to 1978. At Alabama, he had 202 tackles, 6 fumbles forced and 4 recovered. As a senior in 1978, he was recognized as a consensus first-team All-American, and helped lead the Crimson Tide to a National Championship in 1978. He was a key player in the set of fourth quarter plays known as "The Goal Line Stand" in the 1979 Sugar Bowl. It was Lyons that delivered what would become a famous line amongst Alabama fans just before the fourth-down play of the sequence. When asked by Penn StatequarterbackChuck Fusina how far the ball was from the goal line, Lyons replied, "'Bout a foot. You better pass." Alabama was 31-5 during his years as a player.
The two joined Joe Klecko and Abdul Salaam on the Jets' defensive line to form one of the top defensive lines in the NFL, known as the "New York Sack Exchange." The four combined for 66 sacks in 1981 which helped propel the Jets to their first playoff berth since 1969. In November 1981, Salaam, Gastineau, Klecko and Lyons were invited to ring the ceremonial opening bell at the New York Stock Exchange that served as the inspiration for their nickname.
Lyons was involved in one of the best-known plays in NFL lore. During the Jets' 14-13 victory over the Buffalo Bills at the Meadowlands on October 5, 1986, Lyons attempted to sack Buffalo quarterback Jim Kelly and then started to punch him repeatedly after the ball was thrown for an incompletion. Lyons was flagged for a personal foul by referee Ben Dreith for "giving him the business." Dreith mistakenly assessed the foul against number 99, which was Gastineau's number, instead of calling Lyons' number 93.
Lyons missed playing time during the 1987 season when his wife, Kelly, and son, Martin Anthony "Rocky" Lyons Jr., were involved in a serious traffic accident in Alabama. Later the same season, during a Monday Night Football game, Lyons blocked former Alabama teammate and Hall of FamerDwight Stephenson in what Dolphins players and coaches labeled a 'cheap shot' that ended his career.
While a player with the Jets, a series of events — the birth of his eldest son, the passing of his father, and the passing of a little boy to whom Lyons had been a Big Brother — inspired him to establish the Marty Lyons Foundation to work with terminally ill children, providing them wishes. He won the Walter Payton Man of the Year Award in 1984 as a result of that work. In December 2011, Lyons was honored by the Heisman Trust as the recipient of the sixth annual Heisman Humanitarian Award for his work with his Foundation.
Lyons is currently the Jets radio analyst and chairman of the Marty Lyons Foundation. He has been enshrined in the State of Alabama Hall of Fame (2000), Suffolk and Nassau County Sports Hall of Fame (2001 & 2002, respectively), Maryland Sports Hall of Fame (2004), the Tampa Bay Sports Club Hall of Fame (2007), and the College Football Hall of Fame (2011).
Lyons and his wife, Christine, have three children named Luke, Megan, and Jesse. Rocky, his only child from his first marriage, is a physician in Alabama.