Nóirín Ní Riain (born 12 June 1951) is an Irish singer, writer, teacher, theologian, and authority on Gregorian Chant (plainchant, plainsong).

Born in Caherconlish, County Limerick, Ní Riain began singing lessons at age seven.

She has performed in the Royal Festival Hall with Sinéad O'Connor, with the American composer John Cage, with the sons of Karlheinz Stockhausen (Markus and Simon), with Paul Winter at summer and winter solstice concerts in the Cathedral of St John the Divine in New York, and with the Scola Gregoriana of Notre Dame University, Indiana, where she performed the leading role in Anima, by Hildegard von Bingen.

[5] As a child, Ní Riain often visited Glenstal Abbey in Murroe to listen to the chants of the Benedictine monks.

[7] On 29 July 2017, she was ordained as the Rev Nóirín Ní Riain, minister in the One Spirit Inter Faith Seminary Foundation and performs wedding, naming and divorce ceremonies.