The crash happened on the 22000 block of Mulholland Highway just after 1 p.m.
Los Angeles County sheriff's officials say the man was riding a bike eastbound when he and a patrol car traveling in the same direction collided.
The cyclist was pronounced dead at the scene. The coroner's office identified him as 65-year-old Milton Everett Olin Jr. of Woodland Hills.
The deputy in the patrol vehicle was transported to a hospital with minor injuries.
Officials say the deputy was not responding to a call at the time. He was on routine patrol when the crash happened. Investigators are still looking into the crash.
Anyone with information about this incident was asked to contact the Los Angeles County Sheriff's Department's Malibu/Lost Hills Station at (818) 878-1808.