Siobhan Maire Fahey (born 10 September 1958) is an Irish singer whose vocal range is a light contralto. She was a founding member of the British girl group Bananarama, who have had ten top-10 hits including the US number one hit single "Venus".

She later formed the musical act Shakespears Sister, who had a UK number one hit with the 1992 single "Stay". Fahey joined the other original members of Bananarama for a 2017 UK tour, and, in 2018, a North America and Europe tour. She is the first Irish-born woman to have written two number one singles on the Irish charts.