Clay announced Tuesday that he is throwing his support behind Democrat Karen Freeman-Wilson, one of the front-runners in the mayoral race.
Freeman-Wilson is a former state attorney general and Gary city court judge.
Clay is not seeking re-election because he is being treated for prostate cancer.
"I support Karen Freeman-Wilson, because at this time she's the best qualified person for the job," Clay said.
"Mayor Clay has determined that I am the best person to lead the city in a time of great challenge but even greater promise," said Freeman-Wilson.
Freeman-Wilson is running against nine other candidates for Gary mayor.
The election is May 3.
