Jerry Brown, California's "Gov. Moonbeam" in the 1970s and '80s, is running for mayor in 1998.
The former two-term Democratic governor announced his candidacy Tuesday and promised to work as a catalyst for change if elected.
He said he is starting a grass-roots campaign and will not accept more than $100 a donor.
"Oakland has been pushed around," he said. "It's often been shortchanged for the benefit of other people."
The 59-year-old Brown, who now spreads his views as host of a radio talk show, has long been rumored to be interested in succeeding two-term Mayor Elihu Harris.
City Council member Ignacio De La Fuente, college professor Ed Blakely and Audrey Rice-Oliver also have declared their candidacies.
Brown served as governor from 1975 to 1983 and was one of the youngest ever to do so. He also ran unsuccessfully for president three times _ in 1976, 1980 and 1992 _ and was rejected in his bid last spring for a seat on Oakland's Port Commission.
San Francisco Mayor Willie Brown, who was an Assembly member when Brown was governor, said he thought Brown has a good chance at the Oakland job. "He is a man of great talent and modest appearance," Willie Brown said.
Brown, who was educated as an attorney, spent time in a seminary and later worked with Mother Teresa. He earned the "Moonbeam" tag from the late Chicago newspaper columnist Mike Royko for his affinity for Eastern mysticism and back-to-basics liberalism.