In 1935 Sheehy-Skeffington married Andrée Denis, a French graduate of the Sorbonne, with whom he had two sons and one daughter. Like her husband, Andrée Sheehy-Skeffington was a socially-involved campaigner and an active member of the Irish Housewives Association. She later wrote a biography of her husband, Skeff: A Life of Owen Sheehy Skeffington, 1909–1970. They resided at Hazelbrook Cottage, Terenure, Dublin. Sheehy-Skeffington became a lecturer in French at Trinity College Dublin, where he was elected in 1954 as a member of the 8th Seanad Éireann by the Dublin University constituency. He was re-elected in 1957, but lost his seat in 1961. He was returned to the 11th Seanad in 1965 and was re-elected for a final time in 1969. In the Seanad he was known as a champion of human rights and an opponent of authoritarianism, and campaigned for an end to corporal punishment in Irish schools. He was an atheist and helped set up the Humanist Association of Ireland. He was also a co-founder and active member of the Irish Association for Civil Liberty, which he co-founded in 1948 with the writer Seán Ó Faoláin and others. In the late 1950s the memorialist Peter Tyrrell began a long-lasting correspondence with him. Sheehy-Skeffington encouraged Tyrrell to write his autobiography, which was published posthumously and helped to expose the brutal conditions in Irish Industrial schools, and in Letterfrack in particular. After Tyrrell committed suicide in 1967 the only clue to his identity was a card addressed to Sheehy-Skeffington. The National Library of Ireland houses Sheehy-Skeffington's papers. His daughter, Micheline Sheehy-Skeffington, challenged perceived gender inequality at NUI Galway. She was one of 46 people from across the campus to apply for a post of senior lectureship in 2008, was shortlisted for interview, was interviewed, but - upon being unsuccessful - took a case which pressured Galway to introduce gender quotas for promotion schemes and "inclusivity and unconscious bias training programmes" for workers.
Memorial Award
Since 1973, Trinity College Dublin has offered the Owen Sheehy-Skeffington Memorial Award - a bursary worth 1,500 euros awarded annually - as a maintenance grant or as a travel award in alternate years. The criteria for the award include a combination of academic promise and financial need. The maintenance grant is available to senior freshmen or junior sophisters studying French at Trinity College, while the travelling scholarship may be granted to any student attending a centre of higher education in Ireland.