The Birthday Massacre (abbreviated TBM) is a Canadian rock band, formed in 1999 in London, Ontario, and currently based in Toronto, Ontario. The current lineup consists of lead vocalist Sara 'Chibi' Taylor, rhythm guitarist Michael Rainbow, lead guitarist Michael Falcore, keyboardist Owen Mackinder, drummer Philip Elliott, and bassist Brett Carruthers.

When the band formed in 1999, they were known as 'Imagica'. This name was inspired by the 1991 fantasy novel Imajica by Clive Barker. In 2002, they changed the name to The Birthday Massacre after one of their earlier songs in order to avoid confusion with another group. The song The Birthday Massacre was then renamed Happy Birthday. According to their vocalist Chibi: "it kind of works well for the music that we're making. Sort of contrasty, you know? Birthday, and massacre. Light, and dark. Cute, and evil".

The band has released nine studio albums: Nothing and Nowhere (2002), Violet (2005), Walking with Strangers (2007), Pins and Needles (2010), Hide and Seek (2012), Superstition (2014), Under Your Spell (2017), Diamonds (2020), and Fascination (2022).

They also issued the DVD Blue (2005), the live album/DVD Show and Tell (2009), the demo album Imagica, and the EPs Violet (2004), Looking Glass (2008), and Imaginary Monsters (2011).