The Department of Foreign Affairs has confirmed Bernard Phelan is "now on his way home to his family."
The 64-year-old Tipperary native has been in an Iranian prison since his arrest last year.
He was jailed in October as he took a picture of a mosque during protests against the Iranian regime.
Bernard was imprisoned alongside French national, Benjamin Briére, in Mashhad Central Prison.
President Michael D. Higgins said Mr Phelan's release is a "positive outcome".
He said: "Mr Phelan’s release will come as a particular relief to Bernard’s father, Vincent, with whom I have been in correspondence, and to all of his family and friends who have worked with such dignity to secure his return home.
"As President of Ireland, I strongly welcome his release by the Iranian authorities, after what I know has been a very distressing time.”
