At eight years old, she began performing with Disirt Tola, a local band, with which she toured the United States at the age of fourteen.

[citation needed] In the mid-1980s, Shannon studied the accordion with Karen Tweed[3] and the fiddle with Frank Custy, and performed with the band Arcady, of which she was a founding member.

[2] Shannon began her own recording career in 1989, working with producer John Dunford and musicians such as Adam Clayton, Mike Scott and Steve Wickham.

She left the group shortly after Wickham's departure, after Scott forced The Waterboys back towards a more rock and roll sound.

[1] Sharon's track, "Cavan Potholes", written by Dónal Lunny is featured on the 1996 compilation Common Ground: Voices of Modern Irish Music.

[2] Her 2000 album, The Diamond Mountain Sessions, which included vocals from a wide variety of artists, was also a commercial success, being certified triple platinum.

Shannon has also worked with Jackson Browne, the band Coolfin, Dónal Lunny, Moya Brennan, Kirsty MacColl, Christy Moore, Sinéad O'Connor, Paul Brady, Liam O'Maonlai, Mundy and John Prine, amongst others.

In 2004, Shannon released the album Libertango with guest spots from Róisín Elsafty, Sinéad O'Connor and Kirsty MacColl.

A live version of Galway Girl recorded with Mundy was the most downloaded track in Ireland in 2007, winning a Meteor Award.