Amanda Bynes was arrested for DUI in West Hollywood early this morning ... TMZ has learned.
Law enforcement sources tell us, Bynes was attempting to pass a cop car in her black BMW ... when she sideswiped the right rear panel of the vehicle. She was pulled over and cops determined she was not fit to be behind the wheel.
We're told the 26-year-old actress was busted at 3 AM ... she's still behind bars.
According to her booking sheet, Bynes is 5'7" and 125 lbs. Her bail has been set at $5,000.
Bynes has been frequenting the Hollywood party scene recently, hitting up several clubs over the last few weeks.
Just last month -- on St. Patrick's Day -- TMZ cameras saw Bynes leaving Greystone Manor, and thought she appeared to be extremely intoxicated. One of our cameramen even warned the valet not to let Amanda drive, but she got into the driver's seat anyway ... and took off (below).
A week before that, Amanda bolted from a cop while he was writing her a ticket. She was pulled over for talking on a cell phone, and while the cop was writing her up ... she drove away.
Amanda later swung by the police station and signed the ticket. So far, she hasn't faced additional charges stemming from that incident.
We just got Amanda's mug shot ... it's to DYE for!