Tourmakeady, County Mayo, Ireland
He was educated, as a boarder, at St. Mary's College, Galway. He began a career as a teacher, but gave it up for the stage. He starred in the premiere of Brian Friel's play Translations in 1980 in Derry, while he was a member of the Field Day Theatre Company, founded by Brian Friel and Stephen Rea. Lally was also one of the founding members of the Druid Theatre Company. He played the role of Miley Byrne in the RTÉ soap Glenroe, reprising the character that he played earlier in the Bracken T.V. series in 1978. Lally also enjoyed some musical success when The By-road to Glenroe went to the top of the Irish charts in 1990. He has also done voice-over work on Irish television.
In 1979, Lally won a Jacob's Award for his performance as Miley in Bracken.
In 1994, Lally played Fiona's kind grandfather, Hugh, in The Secret of Roan Inish.
Mick Lally is a fluent speaker of the Irish language, and his children study in Irish-speaking schools (gaelscoileanna). He is currently (December 2008) appearing in the Irish-language soap Ros na Rún.
Lally classifies himself as an atheist and regards religion as nonsense and "codology".
Mick Lally provides the voice of Brother Aidan in The Secret of Kells, an animated film directed by Tomm Moore of Cartoon Saloon which premiered at the Jameson Dublin International Film Festival in February 2009. The Secret of Kells was nominated in the category of best animated film at the 82nd Academy Awards.