"Makes Me Wonder" is the first single released from Maroon 5's second album, It Won't Be Soon Before Long (2007). It premiered on the Las Vegas radio station KMXB, and became an instant hit worldwide. Upon release, the song set a record for the biggest jump to number-one in the history of the Billboard Hot 100 chart, rising from number 64 to number-one. However, the record was later broken by Kelly Clarkson's 2009 single, "My Life Would Suck Without You".

"Makes Me Wonder" also became the band's first number-one on the Billboard Hot 100 chart. The song won the Grammy Award for Best Pop Performance by a Duo or Group with Vocal at the 50th Grammy Awards, their second song to win the award. The song was among the most successful of 2007, and was their biggest hit until the release of "Moves like Jagger" by the band in 2011.

Despite the song's commercial success, critical reception was mixed. It was ranked No. 49 on Rolling Stone's list of the 100 Best Songs of 2007. Maroon 5 performed the song in May 2007 on The Tonight Show with Jay Leno.

This song was used in Rock Band games as DLC.

Levine began writing parts of "Makes Me Wonder" years before its release in 2007. Maroon 5 recorded a demo of it, which was one of their firsts while on the "road". The band however put the track aside, and years later revisited it for Won't Be Soon Before Long. Levine recalled that the song "kept coming up because the label loved it". After taking a break from their previous studio sessions for Won't Be Soon Before Long, which was intended to gain "perspective" with the tracks, Maroon 5 regrouped at Glenwood Place Studios in Burbank, California. There, they "rethought a couple of songs and we went back and recut about three songs".

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