Celtic Woman's ‘Decade’ was released in 2015 and is a 4CD set celebrating the first 10 years of the group’s performances. There are 60 tracks spread across the four discs with 15 songs on each, divided thematically to highlight different aspects of the musical range of Celtic Woman.

‘Decade’ is the definitive collection of Celtic Woman tracks. Performers on this album are vocalists Chloë Agnew, Órla Fallon, Lisa Kelly, Méav Ní Mhaolchatha, Hayley Westenra, Lynn Hilary, Alex Sharpe, Lisa Lambe, Susan McFadden, and violinist Máiréad Nesbitt.

CD1 - 'The Songs' features popular numbers that Celtic Woman have performed in live shows such as ‘You Raise Me Up’ and ‘Bridge Over Troubled Water'.

CD2 - 'The Show' features Celtic Woman performing the big songs and dramatic pieces that have been part of the stage show over the 10 years including ‘The Voice’ and ‘O, America’.

CD3 – 'The Tradition' features Celtic Woman performing the traditional based songs and some of the best know Irish ballads that have been an intrinsic part of their show from the beginning, including ‘Níl Sé’n Lá’ and ‘My Lagan Love’.

CD4 – 'The Classics' features Celtic Woman performing classical music and classically inspired pieces with an emphasis on the spiritual and uplifting. Tracks include ‘Ave Maria’ and ‘Walking In The Air’.