Longley was educated at the Royal Belfast Academical Institution and subsequently read Classics at Trinity College, Dublin, where he edited Icarus. He was Professor of Poetry for Ireland from 2007 to 2010, a cross-border academic post set up in 1998, previously held by John Montague, Nuala Ní Dhomhnaill and Paul Durcan. He was succeeded in 2010 by Harry Clifton.

In North America, Michael Longley is published by Wake Forest University Press. His wife Edna Longley is also an influential critic on modern Irish and British poetry.

Gorse Fires (1991) won the Whitbread Poetry Prize. The Weather in Japan (2000) won the T. S. Eliot Prize and the Hawthornden Prize. He holds honorary doctorates from Queen's University Belfast (1995) and Trinity College, Dublin (1999) and was the 2001 recipient of the Queen's Gold Medal for Poetry. Longley was appointed Commander of the Order of the British Empire (CBE) in the 2010 Birthday Honours.