I’m Not the Only One

"I'm Not the Only One" is a song recorded by English singer Sam Smith from their debut studio album, In the Lonely Hour (2014). It was written by Smith with Jimmy Napes, who also produced the song along with Steve Fitzmaurice. Capitol Records released it to digital download on 31 August 2014 as the album's third single in the United Kingdom and on 24 September 2014 as the album's second single in the United States; an alternative version with American rapper A$AP Rocky was also released.

A piano soul ballad, anchored by orchestral strings and a gospel structure, "I'm Not the Only One" deals with themes of infidelity in a relationship and was inspired by a marriage of someone Smith and Napes knew. It received a positive response from critics, who praised their emotional vocals and its instrumentation. Commercially, the song was another success for Smith, becoming a number one hit in South Africa, top-three hit in the United Kingdom, a top-five hit in the United States, and a top-ten hit in over ten countries. It is certified Diamond in Australia, seven-times platinum in the US, and multiplatinum in ten additional countries. It was the bestselling international song in South Korea in 2016. A music video featuring actors Dianna Agron and Chris Messina was released on 1 August 2014 and it features content similar to the song's lyrics.