Since 2012, Farrar is touring with Maroon 5 - as an additional band member - on guitars, occasionally on the bass guitar, percussion, additional keyboards, backing vocals, turntables and providing samples and other special effects (using the MPC). He co-wrote and co-produced a few of the band's songs on almost all of their studio albums and also remixed one of their songs, which is called "Woman", on Call and Response: The Remix Album, released in 2008. On August 31, 2012 - during a show in Argentina on the Overexposed World Tour - Farrar filled-in for Mickey Madden on the bass guitar for the very first time. He subsequently filled-in for Madden on the next few shows of the tour.
His father, John Farrar, was a member of The Shadows and also carved a successful songwriting career, penning many of Olivia Newton-John's big hits as well as producing nearly every one of her albums during her most successful years. His mother, Pat Carroll, was a successful Australian pop singer in the 1960s. He attended The Buckley School. Sam is married to Stephanie Eitel, formerly a member of the band Agent Sparks. Their daughter Vesper Pearl Farrar was born on August 6, 2009 and their son Flynn Roscoe Farrar was born on January 14, 2014.