"The Hardest Part" is a song by British rock band Coldplay. It was written by all four members of the band for their third album, X&Y. A piano-based ballad song, it begins with a piano melody, followed with electric guitar lines, that accompanies slow-tempo drumming.

Coldplay are a British rock band formed in London in 1997, consisting of vocalist and pianist Chris Martin, lead guitarist Jonny Buckland, bassist Guy Berryman, drummer and percussionist Will Champion, and manager Phil Harvey. They are best known for their live performances, having also impacted popular culture with their artistry, advocacy and achievements.