Seán Lucy was born on March 12, 1931, in Mumbai, India. His father was an Irish officer in the British army who served in the military until 1935, at which time he resettled with his family in Ireland. Seán Lucy earned his bachelor's and master's degrees at the University College, Cork (National University of Ireland), under his English name, John F. Lucy. In 1954, Lucy moved to England and married Patricia Kennedy, his first wife, with whom he had five children: Catherine, Brendan, John, Frances, and Fintan. While in England, Lucy served two years as an education officer in the British army and four years as Senior English Master at the Christian Brothers Prior Park College in Bath.
Lucy returned to Ireland in 1960, and joined the English faculty at University College, Cork, where he rose to the rank of professor and became department chair. Lucy wrote and edited critical works on English and Irish poetry and prose, such as Love Poems of the Irish (1967). He also published his own creative works in poetry, including Unfinished Sequence and Other Poems (1979). In 1979, he co-founded the University College, Cork, Summer School in Irish Studies for American students. During the 1980-81 academic year, he served as a visiting professor in the English department at Loyola University, Chicago. Following his early retirement from University College, Cork, in 1988, Seán Lucy moved to Chicago and married his second wife, fellow poet Susan Leah Lederman. He offered courses in Irish literature at Loyola University, the Newberry Library, and the Irish-American Heritage Center. He died on July 25, 2001, following a heart attack.