Who Knew

"Who Knew"
Single by Pink
from the album I'm Not Dead
B-side	"Disconnected"
Released	May 8, 2006 (2006-05-08)
Studio	Conway (Hollywood, California)
Genre	Pop[1][2]
Length	3:28
Label	LaFace
Songwriter(s)	Pink Max Martin Lukasz Gottwald
Producer(s)	Max Martin Dr. Luke
Pink singles chronology
"Stupid Girls" (2006) "Who Knew" (2006) "U + Ur Hand" (2006)
Music video
"Who Knew" on YouTube

"Who Knew" is a song by American singer Pink from her fourth studio album, I'm Not Dead (2006). Written by Pink, Max Martin and Lukasz "Dr. Luke" Gottwald, the song was originally released on May 8, 2006, by the LaFace label to radio as the album's second single, but was only a moderate success. The song saw more success upon its re-release in the United States in June 2007. Musically, "Who Knew" is a pop song. Lyrically, it regards the loss of a good friend of hers.

Upon its release, "Who Knew" was well received by music critics, who acclaimed it as a solid song on the album and lauded the lyrical content. It faced comparisons for having similarities with Kelly Clarkson's 2004 single "Since U Been Gone", also written by Martin and Dr. Luke. The song was commercially successful worldwide, where it peaked in the top five in countries including Australia, the United Kingdom, and component charts in the United States. The song is also Pink's longest chart runner on the Hot 100, spending 36 weeks on the chart. The song was later certified Platinum in the United States by the Recording Industry Association of America (RIAA).

The accompanying music video to the song was directed by Dragon and was released in May 2006, where it shows Pink singing at a county fair, with a storyline about two young lovers who end up being separated after the man begins using drugs. The song has been performed on many of Pink's world tours, including I'm Not Dead Tour, Funhouse Tour and its extension tour Funhouse Summer Carnival Tour.