Buffini was born in Cheshire to Irish parents, and attended St Mary's College at Rhos-on-Sea in Wales as a day girl.
[3] Loveplay followed at the RSC in 2001, then Dinner at the National Theatre in 2003 which transferred to the West End and was nominated for an Olivier Award for Best Comedy.
[4] She followed it with Marianne Dreams a dance play with choreographer Will Tuckett, based on Catherine Storr's book.
Buffini advocates big, imaginative plays rather than naturalistic soap opera dramas, and is a founder member of the Monsterists, a group of playwrights who promote new writing of large scale work in the British theatre.
[9] Buffini adapted her play A Vampire Story for the screenplay of Neil Jordan's film Byzantium released in 2013.