Siobhan Hayes (born April 23, 1975) is an actress, best known for playing Abi Harper in the BBC sitcom My Family and her character "Sandy", the office trainee in the BBC Radio series Absolute Power.

Hayes portrayed Abi Harper, as a dimwitted and clumsy student in the British sitcom My Family, a role she held between 2002 and 2008, when the character became a nun, allowing a potential return. She has also made guest appearances in Little Britain, Paul Merton: The Series, Agatha Christie's Marple, Birds of a Feather, and The Bill.

Her early appearances included playing a pupil of class 5C from 1991 onwards in the series Up the Garden Path.

On 15 October 2005, she appeared on the third series of the BBC's pro celebrity dancing show Strictly Come Dancing, dancing with professional Matthew Cutler. The couple were the first to be eliminated. On 1 February 2008, it was announced that Hayes would be joining EastEnders, with the role of Melinda, the partner of the show's returning Ricky Butcher played by Sid Owen. This is Siobhan's second role in EastEnders, as she played Jane on 4 July 1991.

Hayes starred in the 2011 British live action 3D family comedy film Horrid Henry: The Movie, playing the role of the titular character's mother.