Officer Christopher Hughes, 39, was booked over the weekend, CHP Officer Lizz Dutton said.
Dutton said the case was reported as a medical emergency Saturday afternoon at Hazel Avenue and Piedra Way.
Hughes' vehicle was spotted in a lane of the road and he slumped over the steering wheel, Dutton said.
When CHP officers responded, they found Hughes was found to be intoxicated, the CHP said.
Sacramento police Sgt. Norm Leong confirmed the arrest and said the department is conducting an administrative investigation.
KCRA.com contributed to this report.