Louis Michael Cullen (born 1932) is an Irish diplomat, academic, historian, author and Japanologist. He is Professor of Modern Irish History at Trinity College in Dublin.
Cullen's family came from New Ross in County Wexford. He earned a Master's degree at University College Galway. he was awarded a doctorate at the London School of Economics.
Cullen joined the Irish Diplomatic Corps. He was posted Paris where he began research into the historic trading links between Ireland and France.
In 1963, he became a lecturer in history at Trinity College. He was appointed professor in 1972.
In an overview of writings by and about Cullen, OCLC/WorldCat lists roughly 70+ works in 150+ publications in 7 languages and 4,600+ library holdings.