"Upside Down" is a song written, co-produced, and performed by Jack Johnson for the film Curious George. It is the first track and first single from the album Sing-A-Longs and Lullabies for the Film Curious George, which was released in February 2006.

It peaked at #38 on the Billboard Hot 100 and was Johnson's sole US Top 40 hit until "You and Your Heart" in 2010. Released as a single in the UK on May 22, 2006, it debuted at #45 in the UK Singles Chart the day before its physical release via download sales alone. The following week, it became Jack Johnson's second UK Top 40 entry, peaking at #30. It has been certified Platinum by the RIAA for sales of over 1,000,000 in the US alone.

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