Rahm Emanuel's new Web site promises that a special announcement from him is imminent.
ChicagoforRahm.com says the video announcement from Emanuel will come Sunday.
Emanuel left his job as chief of staff for President Barack Obama on Friday.
He's largely expected to be moving back to Chicago to announce a run for mayor.
The new Web site highlights Emanuel's ties to Chicago, noting his three terms representing a North Side district in Congress before his move to the White House.
His online biography says he is "deeply rooted in the life of the city."
Emanuel had been careful not to launch his mayoral bid from Washington. He didn't want to offend Chicago voters, who are expected to make him work to prove he truly deserves the job.