A sheriff's official says the 24-year-old starlet started serving her term Thursday after turning herself in at a jail facility just after 5 a.m.
Lohan was sentenced in April to 120 days in jail for violating her probation in a 2007 drunken driving case by taking a necklace from a Venice jewelry store without permission. Lohan applied to serve house arrest, but the accommodation hadn't been finalized when she appeared in court earlier this month and pleaded no contest to misdemeanor grand theft.
Los Angeles County Sheriff's Department spokesman Steve Whitmore says Lohan is expected to serve about 35 days of her sentence.
Whitmore says Lohan was cooperative when she turned herself in, and it took about an hour for her to be fingerprinted and booked. No new mugshot was taken.