"God Only Knows" is among the several songs that Brian Wilson and Tony Asher wrote for the Beach Boys' "Pet Sounds" album. Asher felt that it was the pair's most effortless collaboration, remembering that Wilson "spent more time tweaking the instrumental part than we did writing the words!" Recalling "God Only Knows", Wilson acknowledged that he had "not written that kind of song" before and said, "I think Tony had a musical influence on me somehow. After about ten years, I started thinking about it deeper ... And I remember him talking about 1944 standard 'Stella by Starlight' and he had a certain love for classic songs." Asher concurred that he felt he inspired Wilson to write the song.