TMZ has learned "Three's Company" star Joyce DeWitt was arrested for DUI on July 4th in El Segundo, California.
Law enforcement sources tell us DeWitt drove past a barricade Saturday afternoon -- and when an officer approached her, she smelled like booze. She was given field sobriety tests and then arrested for suspicion of DUI.
The 60-year-old actress, who played Janet Wood on the 80's sitcom, posted bail for $5,000.
The Regal Beagle wouldn't comment.