The convention runs Sept. 4-6. Democratic Party officials did not announce a date or time, and an Emanuel aide said those details had not yet been set.
Emanuel was President Barack Obama's first chief of staff and earlier served as a Democratic congressman.
As Democratic convention organizers announced news of Emanuel's speech, they also listed these additional convention speakers: California Attorney General Kamala Harris; Colorado Gov. John Hickenlooper; former Virginia Gov. Tim Kaine, who is running for the Senate; Sen. John Kerry of Massachusetts, who was the party's 2004 presidential nominee; Maryland Gov. Martin O'Malley; Massachusetts Gov. Deval Patrick; and former Ohio Gov. Ted Strickland. The keynote speaker for the gathering will be San Antonio Mayor Julian Castro.