"On Fire" is a song recorded by Belgian singer Loïc Nottet, and released for digital download on 30 November 2018 by Sony Music Entertainment as the second single from his second studio album Sillygomania. It was written by Nottet along with Sacha Skarbek, while production was handled by Skydancers. Musically, "On Fire" is a midtempo, urban-inspired electropop song similar to Nottet's past work. Its lyrics are directed at the criticism the singer had received during his career, and discuss topics such as worthlessness, perseverance and rebirth. Four personalities are reflected on the track, as Nottet wanted to personify the moods he was in while composing the song.

Sacha Skarbek is a British songwriter and producer. He is best known for co-writing James Blunt's hit singles "You're Beautiful" and "Goodbye My Lover" as well as Miley Cyrus' hit song "Wrecking Ball". Skarbek has worked with artists such as Adele, Lana Del Rey, Jason Mraz, Tears for Fears, Duffy and many more.