Máire grew up as the eldest child of a musical family in the remote parish of Gweedore (Gaoth Dobhair), a Gaeltacht area in County Donegal, where the Irish language and tradition continue to flourish.

[9] Her mother Máire (née Ní Dhúgáin or Duggan in English) was a music teacher and her father, Leo Brennan, was a member of a cabaret band with whom she performed as a child.

After leaving secondary school, Brennan spent a few years at the Royal Irish Academy of Music in Dublin studying the harp, the piano and singing.

[11] After enjoying a decade of being among the world's foremost Irish musical groups, Clannad graduated to chart success in 1982 with the album Magical Ring.

Her sister, Eithne Ní Bhraonáin, spent a couple of years with Clannad in the early 1980s, and went on to pursue a very successful solo career as Enya.

She accepts the Celtic label, but has at times indicated a slight discomfort with being seen as "New Age" as much of her music is strongly Christian, with several of her songs centring on maintaining a relationship with Jesus.

was published and she also performed her song "Perfect Time" live at World Youth Day in Rome in front of crowds of pilgrims and Pope John Paul II.

In film, she was featured vocalist on King Arthur (2004), co-writing the title theme "Tell Me Now (What You See)" with Hans Zimmer and wrote additional music score for To End All Wars (2001).

Brennan has collaborated with many other musicians, including Chicane, Alan Parsons, Bono, Robert Plant, Van Morrison, Michael McDonald from the Doobie Brothers, Bruce Hornsby, Joe Elliott, The Chieftains, Paul Young, Paul Brady, Michael Crawford, Joe Jackson and Ronan Keating.

[21][22] In 2009, Brennan recorded the official soundtrack on Maryland Public Television documentary film 'Intrepid Journal' which documents 50 years of American foreign policy, from World War II to the September 11 attacks.

[23] In April 2010, Moya released a new studio album with harpist and live band member Cormac de Barra.

Brennan was the featured headliner for the Atlanta Celtic Christmas concert, recorded live by Georgia Public Broadcasting on 18–19 December 2010.

This annual festive event at Emory University's Schwartz Center spans music and dance from Irish, Scottish, and Appalachian traditions.

[26] Moya Brennan appeared as well on the album "Excalibur III – The Origins" written by Alan Simon, a musician who comes from Brittany (France).

Between August 2008 and February 2009, two new members joined Moya's band, the first changes since her Two Horizons Tour, including Irish singer Daithí Rua.

[34] Brennan and Clannad are credited with the creation of contemporary Celtic music and are held in high esteem for their vast contribution to bringing new life to old Irish songs.

[2] Brennan's inauguration ceremony is set to take place on 6 April 2024, at a gala ball held at The Bonnington Hotel in Dublin.

[40] Brennan wrote an autobiography called The Other Side of the Rainbow in 2000, in which she recalls her upbringing as the eldest of nine siblings in rural Donegal.

Along with the highs of success in the music business, she also recounts low periods where alcohol, drugs and an abortion made her re-evaluate her life.

[45] Brennan performs various concerts in aid of charities and groups that work to rehabilitate those affected by drug addiction and alcohol dependency.

She also practices religion with her family in Dún Laoghaire, at a church which also reaches out to young people affected by drug and alcohol misuse.

With family band Clannad, Brennan has recorded numerous songs about the needed protection of the landscapes in Ireland and the devastation of pollution around the world.

[46] In 1985, Brennan along with her band members in Clannad donated their song "Almost Seems (Too Late To Turn)" to Children in Need, becoming the British charity appeal's first official single.