The 39-year-old sat out the entire out 2006-07 season after spending 2005-06 with the Boston Bruins, when he recorded five goals and 27 assists in 61 games.
"I have been fortunate to be an NHL player since 1988," Leetch said in a statement. "I missed being in the NHL this past season, but believe it was the right time for me to stop playing."
Leetch was originally drafted by the New York Rangers ninth overall in the 1986 entry draft and spent parts of 16-plus seasons on Broadway.
In 1991-92, he became only the fifth defenceman in NHL history to reach the 100-point plateau and finished the year with 102 points (22-80).
He was moved to the Toronto Maple Leafs in a trade deadline deal in 2003-2004 and after the lockout spent his final season with the Bruins.
In 1,205 games, he scored 247 goals with 781 assists - one of only seven NHL defenceman to record 1,000 points.
Leetch is also the only American-born player to win the Conn Smythe Trophy as playoff MVP after helping the Rangers end a 54-year Stanley Cup drought in 1994.