Ledyard played junior with the Fort Garry Blues and Saskatoon Blades and then signed as a free agent with the New York Rangers in 1982. He began his pro career in the CHL as a fine playmaking defenceman on the Tulsa Oilers. In 1984, he was presented the Bob Gassoff Award as the most improved defenceman in the league.
Ledyard split the 1984-85 season between the AHL and the Rangers. Following the Blueshirts' elimination from the first round of the playoffs, the young rearguard joined Team Canada at the 1985 World Championships. Part-way through the 1985-86 season, Ledyard was traded to the L.A. Kings. In 1986-87, he scored a career-high 14 goals and joined the Washington Capitals the next year. Late in the 1988-89 season, Ledyard was traded to the Buffalo Sabres where he found a home as a defensive leader on the club for over four years.
In August 1993, Ledyard sought stability by signing a long-term deal as a free agent with the Dallas Stars. In 1993-94, he scored 46 points and helped to quarterback the power play. He remained with the Stars for three more years as they became a league power. Beginning in 1997-98 Ledyard toiled briefly for Vancouver, Boston, Ottawa, Tampa Bay, and Dallas a second time within a four-year period.
Ledyard would return to the Tampa Bay Lightning for his last season in 2000-01. Ledyard competed for the Brantford Blast for a pair of sesasons before retiring from the game in 2003-04.