Levine has Jewish ancestry on both sides of his family (his father and maternal grandfather were Jewish), and considers himself Jewish,
Adam was born on 18 March in 1979 in Los Angeles, California, United States. Levine is of 3/4 Jewish descent (his father and maternal grandfather are both Jewish), while his maternal grandmother was a Protestant. Levine considers himself Jewish, though according to an interview with The Jewish Chronicle, he "has rejected formal religious practice for a more generalized, spiritual way of life." He chose not to have a Bar Mitzvah as a child because of the custom of receiving Bar Mitzvah gifts, explaining: "I felt as though a lot of kids were trying to cash in ... I just don't think it's the most respectful way to deal with God and beliefs and years and years and years of cultural heritage." Levine is a nephew of journalist and author Timothy Noah, television producer and writer Peter Noah, and economist Jordan Levine.
His parents divorced when he was seven. Growing up, Levine spent weekdays with his mother and weekends with his father. He underwent therapy for his parents' divorce, but called it a "waste of time" explaining that his parents could not "accept the fact that I might have been OK with it. I cried my eyes out and kicked and screamed and said, 'Why?' and all the things you do when you find out. A few days later I was fine but I still had to go to therapy."
Levine describes his family as "very musical" and credits his mother with "start[ing] me out on the path." He also attributes his mother's idols – Simon & Garfunkel, Fleetwood Mac, and The Beatles – to shaping his musical style, calling them "a huge part of my upbringing". Levine attended Brentwood School, where he met Jesse Carmichael and Mickey Madden, his future bandmates. He carried his musical interests to high school, where he states he was "a little rebellious. I didn't want to do the things they were teaching me ... [music] consumed my every thought."