"What Happened to Us" is a song by Australian recording artist Jessica Mauboy, featuring English recording artist Jay Sean. It was written by Sean, Josh Alexander, Billy Steinberg, Jeremy Skaller, Rob Larow, Khaled Rohaim and Israel Cruz. "What Happened to Us" was leaked online in October 2010, and was released on 10 March 2011, as the third single from Mauboy's second studio album, Get 'Em Girls (2010). The song received positive reviews from critics.
A remix of "What Happened to Us" made by production team OFM, was released on 11 April 2011. A different version of the song which features Stan Walker, was released on 29 May 2011. "What Happened to Us" charted on the ARIA Singles Chart at number 14 and was certified platinum by the Australian Recording Industry Association (ARIA). An accompanying music video was directed by Mark Alston, and reminisces on a former relationship between Mauboy and Sean.
Majhid Heath from ABC Online Indigenous called the song a "Jordin Sparks-esque duet", and wrote that it "has a nice innocence to it that rings true to the experience of losing a first love." Chris Urankar from Nine to Five wrote that it as a "mid-tempo duet ballad" which signifies Mauboy's strength as a global player. On 21 March 2011, "What Happened to Us" debuted at number 30 on the ARIA Singles Chart, and peaked at number 14 the following week. The song was certified platinum by the Australian Recording Industry Association (ARIA), for selling 70,000 copies. "What Happened to Us" spent a total of ten weeks in the ARIA top fifty.
The music video for the song was shot in the Elizabeth Bay House in Sydney on 26 November 2010. The video was shot during Sean's visit to Australia for the Summerbeatz tour. During an interview with The Daily Telegraph while on the set of the video, Sean said "the song is sick! ... Jessica's voice is amazing and we're shooting [the video] in this ridiculously beautiful mansion overlooking the harbour." The video was directed by Mark Alston, who had previously directed the video for Mauboy's single "Let Me Be Me" (2009). It premiered on YouTube on 10 February 2011.
The video begins showing Mauboy who appears to be sitting on a yellow antique couch in a mansion, wearing a purple dress. As the video progresses, scenes of memories are displayed of Mauboy and her love interest, played by Sean, spending time there previously. It then cuts to the scenes where Sean appears in the main entrance room of the mansion. The final scene shows Mauboy outdoors in a gold dress, surrounded by green grass and trees. She is later joined by Sean who appears in a black suit and a white shirt, and together they sing the chorus of the song to each other.