"Happier Than Ever" is a song by American singer-songwriter Billie Eilish from her 2021 second studio album of the same name. It was released as the album's sixth single on July 30, 2021, through Darkroom and Interscope Records. An emo and pop-punk song with elements of jazz, it is about Eilish's anger towards a former partner due to a toxic relationship. It opens with soft vocals backed by classical and bass guitars, and transitions into a distorted pop-punk and rock production with electric guitars and snare drums midway. She wrote the song with its producer, Finneas O'Connell, after completing the American leg of her When We All Fall Asleep Tour (2019).

Billie Eilish Pirate Baird O'Connell is an American singer and songwriter. She first gained public attention in 2015 with her debut single "Ocean Eyes", written and produced by her brother Finneas O'Connell, with whom she collaborates on music and live shows. In 2017, she released her debut extended play (EP), Don't Smile at Me. Commercially successful, it reached the top 15 of record charts in numerous countries, including the US, UK, Canada, and Australia.