The 48-year-old "Strahan, Sara and Keke" host made the announcement on "The Tonight Show Starring Jimmy Fallon," saying he expected the retirement to be "really emotional."
Strahan, one of the game's most dominant pass-rushers during 15 seasons with the New York Giants, retired from the NFL in 2008 after helping the Giants beat the New England Patriots to win Super Bowl XLII.
He spent his entire career with the team and was inducted into the Pro Football Hall of Fame in 2014.
He was a seven-time Pro Bowl selection and the league's Defensive Player of the Year in 2001.
Strahan had 22 1/2 sacks in 2001 to set the NFL single-season record, and his 141 1/2 career sacks rank sixth on the NFL list behind Bruce Smith, Reggie White, Kevin Greene, Julius Peppers and Chris Doleman.