Assemblywoman Mary Hayashi received three years' probation and was fined $180, and ordered to stay at least 50 feet from the Union Square store.
The charges were reduced from felony grand theft to a misdemeanor as part of a plea deal.
"This is a person who didn't have any previous arrests, no convictions, no criminal history and she also admitted guilt at a very early stage," said Stephanie Ong Stillman, a spokeswoman for the San Francisco district attorney's office.
Hayashi's attorney, Douglas Rappaport, said she is on medication for a benign brain tumor and that the ailment may have caused her behavior.
Hayashi, a Democrat, was arrested Oct. 25 leaving the store with a white blouse, black skirt and leather pants in a shopping bag.
Her office said at the time she had meant to pay for the clothes but was distracted.