"Idontwannabeyouanymore" (stylized in all lowercase) is a song by American singer Billie Eilish from her debut EP, Don't Smile at Me (2017). Eilish and her brother, Finneas O'Connell, co-wrote the song, with the latter solely handling the production. It was released through Darkroom and Interscope Records on July 21, 2017, as the fifth single from the EP. Musically, the song is pop and R&B track with a jazz and neo soul-influenced melody, that was heavily inspired by Eilish being depressed. Commercially, "Idontwannabeyouanymore" reached number 96 on the Billboard Hot 100. It has also received several certifications, including double-platinum awards from the Mexican Association of Producers of Phonograms and Videograms, A.C. (AMPROFON) and the Recording Industry Association of America (RIAA). The song was performed live during Eilish's 2019 When We All Fall Asleep Tour and her Where Do We Go? World Tour in 2020.
"Idontwannabeyouanymore" was conceived when Eilish was suffering from depression. In an interview with Genius, Eilish stated "I have still dealt with depression. 'Idontwannabeyouanymore' is about times I’ve felt this way. The real truth is that depression can happen to anyone no matter who you are or what you have and there is no shame to admitting that you feel this way. It’s a very real thing and should never be ignored or labeled 'a choice'." She compared the song to her 2017 single "Copycat". On July 21, 2017, "Idontwannabeyouanymore" was released as the fifth single on Eilish's debut EP Don't Smile at Me (2017). "Idontwannabeyouanymore" was written by the singer and her brother Finneas O'Connell, the latter of which also produced it. Studio personnel John Greenham and Rob Kinelski handled the mastering and mixing, respectively.