Maude is reared in the Irish language. Her mother, Máire Nic an Iomaire, is a school teacher from Ballyfinglas. She receives her primary education from her mother on a small island off the coast of Rosmuc, Connemara. Her father, John Maude, is from Cill Bhriocáin in Rosmuc. She attends University College Galway, where she excels in French. She becomes a teacher, working in schools in Counties Kildare, Mayo, and Wicklow. She also works in other capacities in London and Dublin.
Maude is widely praised as an actor. She acts at the University, at An Taibhdhearc in Galway and the Damer in Dublin, and is particularly successful in a production of An Triail by Máiréad Ní Ghráda in 1964, in which she plays the protagonist of the story, Máire Ní Chathasaigh. She herself is a playwright and co-authors An Lasair Choille with poet Michael Hartnett.
Maude begins writing poetry in Irish in secondary school and develops a lyrical style closely attuned to the rhythms of the voice. Though not conventionally religious, she says in an interview that she has a deep interest in the spiritual and that this leaves its mark on her poetry. She is noted as a highly effective reciter of her own verse. Géibheann is the best-known of her poems, and is studied at Leaving Certificate Higher Level Irish in the Republic of Ireland. A posthumous collected edition, Caitlín Maude, Dánta, is published in 1984, Caitlín Maude: file in 1985 in Ireland and Italy, and Coiscéim in 1985.
As a member of the Dublin Irish-speaking community Maude is active in many campaigns, including the establishment of the Gaelscoil (Irish-medium primary school) Scoil Santain in Tallaght, County Dublin.
Maude is a sean-nós singer of distinction. She makes one album in this genre, Caitlín, released in 1975 on Gael Linn Records and now available as a CD. It contains both traditional songs and a selection of her poetry.
Maude marries Cathal Ó Luain in 1969. They have one child, their son Caomhán.
In 2001, a new writers’ centre in Galway, Ionad Schribhneoiri Chaitlin Maude, Gaillimh, is named in her memory.