Multnomah County Commissioner Jules Bailey is scheduled to announce for Portland mayor on Saturday.
Bailey will make the announcement at a morning event where he plans to collect 100 city voter signatures to qualify to run by petition.
The other major candidate in the race, State Treasurer Ted Wheeler, qualified by paying a $50 filing fee.
The event begins at 9:30 a.m. on Jan. 9 at Hatch, 2420 N.E. Sandy Blvd.
Bailey is expected to make remarks about why he is running for mayor at the beginning of the event.
Bailey has limited his contributions to $250 and has reported receiving $2,900 since letting it be known he would run for mayor. His campaign account had already received over $60,000 in previous contributions in 2015, however, leaving him with a current balance of around $44,000 after some expenses.
Wheeler has not limited his contributions and raised over $161,000 last year, most of it after incumbent Mayor Charlie Hales dropped out of the race.