John M. O'Sullivan (18 February 1891 – 9 February 1948) was an Irish politician, cabinet minister and academic.
John M. O'Sullivan was born in Killarney, County Kerry in 1891. He was educated at St. Brendan's, Killarney, Clongowes Wood, Kildare, University College Dublin and the Universities of Bonn and Heidelberg where he was awarded the PhD. He was appointed to the Chair of Modern History at UCD in 1910 and was first elected to Dáil Éireann in 1923 as a Cumann na nGaedhael TD for Kerry North. He was appointed to the Cabinet in 1926, serving under W. T. Cosgrave. In 1926 a report from the Second National Programme Conference was presented to John M. O'Sullivan as the then Minister for Education for Cumann na nGaedhael. The Minister accepted all proposals stated in the report to be recommended as a national curriculum. He served on the Irish delegation to the League of Nations, 1924 and 1928–30. He was elected at every election until 1943 when he lost his Dáil seat. He subsequently retired from politics.
O'Sullivan died in 1948, five years after retiring from politics.