Ann Coates is a fictional singer credited with backing vocals on the 1986 single "Bigmouth Strikes Again" by The Smiths, also included on their album The Queen Is Dead.

In reality, the singer-on-helium effect was achieved by speeding up a regular harmony part by singer Morrissey. Morrissey and co-producer Johnny Marr then jokingly decided to credit this to a fictitious person.

"Her" name is derived from the Manchester district of Ancoats.