He'll join community health care provider APICHA for the 23rd annual parade, which started in 1993 in response to the murder of Julio Rivera and discrimination in schools.
Last year, de Blasio made "history" as the first mayor to march in the parade, according to Councilman Danny Dromm, a parade founder.
More than 40,000 spectators are expected at the parade this year, where the theme will be "Pride - Strength - Unity," organizers said. More than 40,000 spectators are expected.
The parade route, which will follow a lavender line painted down 37th Avenue, begins on 89th Street and ends on 75th Street with a street festival and performances. It kicks off noon, with viewing stands on 79th and 80th streets.