"So Yesterday" is a song recorded by American singer Hilary Duff for her second studio album, Metamorphosis (2003). It was written and produced by The Matrix (a production team consisting of Lauren Christy, Scott Spock and Graham Edwards), with additional writing from Charlie Midnight. The song is influenced by pop rock music, and the lyrics chronicle the protagonist getting over a breakup with her boyfriend, declaring him as "so yesterday". The song received mixed reviews from music critics, with some of them noting its close similarity to Avril Lavigne's works, while others named it one of Duff's best songs ever.

"So Yesterday" premiered on AOL Music's "First Listen" on June 27, 2003. It was serviced to mainstream radio in the United States on July 15, 2003. The song became Duff's first single to chart in the US Billboard Hot 100, reaching number forty-two. It was moderately successful outside the US, reaching top forty in most countries it charted. The song reached number eight in Australia and was certified platinum by Australian Recording Industry Association (ARIA).

The song was accompanied by a music video, directed by Chris Applebaum, which showed Duff playing a prank on her ex-boyfriend. It was successful on various music video channels like MTV and MuchMusic. Duff performed the song on her Metamorphosis Tour and has since performed it on all her concert tours. The song is also featured on the compilations Most Wanted (2005), 4Ever Hilary (2006) and Best of Hilary Duff (2008), and the music video game Band Hero.

...
Wikipedia