The last time they had appeared on stage together was in 2002 during a memorial for another former Beatle, George Harrison, The New York Times said.
McCartney headlined Saturday's "Change Begins Within" benefit concert for the David Lynch Foundation and Starr joined his fellow former band mate for Beatles classics such as "With a Little Help from My Friends," The Times reported.
McCartney unveiled his new song "Cosmically Conscious," which was previously released as a partial excerpt on his 1993 album "Off the Ground."
Other performers at the benefit included Moby, Eddie Vedder, Sheryl Crow, Donovan, Bettye LaVette, Ben Harper and Mike Love.
The David Lynch Foundation is focused on promoting transcendental mediation teachings.