"Big Mistake" is a song by Australian singer Natalie Imbruglia. It was written by Imbruglia and Mark Goldenberg for Imbruglia's debut album Left of the Middle (1997). The song was released as the album's second single on 2 March 1998 by RCA and BMG. Although less successful than "Torn", "Big Mistake" still proved to be a hit in certain territories, reaching number two in Iceland and the United Kingdom, number five in Spain and number six in Australia. It was not released in the United States or Canada.

Natalie Jane Imbruglia is an Australian-British singer-songwriter and actress. In the early 1990s, she played Beth Brennan in Neighbours. Having left the soap opera, she moved to the UK and began a singing career. Her debut single, a cover of Ednaswap's song "Torn" (1997), quickly became a worldwide hit, topped the US Billboard Radio Songs Chart for eleven weeks in 1998, and was listed on 50 Best Songs of 1990s by Rolling Stone. Her debut album, Left of the Middle (1997) was a commercial success, certified multi-platinum in the US, the UK and Australia and eventually sold seven million copies worldwide. Subsequent albums, including White Lilies Island (2001) and Counting Down the Days (2005) did not match commercial success of her debut, but both albums still gained Gold certification in the UK. As of 2021, Imbruglia has released six studio albums and has sold more than ten million copies worldwide. Imbruglia has received various accolades, including eight ARIA Awards, two Brit Awards, one Billboard Music Award, one Silver Clef Award and three Grammy nominations.