Pierce, a 10-time All-Star during his 19-year NBA career, was found asleep behind the wheel of his vehicle on a freeway shortly before midnight on Tuesday, the CHP said in a statement.
Lanes on the motorway had been closed because of a crash, and when they reopened, officers saw a Range Rover stopped in traffic.
"When officers approached, they found the driver, later identified as Paul Pierce, asleep at the wheel," the CHP said. "Officers noted signs of alcohol impairment and conducted a DUI investigation."
The 47-year-old Pierce was arrested on suspicion of driving under the influence of alcohol. His case will be presented to the Los Angeles City Attorney's office for review, the CHP said.
Pierce, who teamed with Kevin Garnett and Ray Allen in Boston as part of the Celtics' "big three," was named Most Valuable Player of the 2008 NBA Finals, in which Boston defeated the Los Angeles Lakers 4-2 to claim a 17th NBA title.
A California native, Pierce attended high school in the Los Angeles area.
He was selected 10th overall in the 1998 NBA draft by the Celtics and also played for the Brooklyn Nets, Washington Wizards, and Los Angeles Clippers before he retired in 2017.