Employing a wide range of critical perspectives and new comparative contexts, Flann O’Brien: Contesting Legacies breaks new ground in O’Brien scholarship by testing a number of popular commonplaces about this Irish (post-) Modernist author. Challenging the narrative that Flann O’Brien wrote two good novels and then retired to the inferior medium of journalism (as Myles na gCopaleen), the collection engages with overlooked shorter, theatrical, and non-fiction works and columns (‘John Duffy’s Brother’, ‘The Martyr’s Crown’, ‘Two in One’) alongside At Swim-Two-Birds, The Third Policeman, and An Béal Bocht. The depth and consistency of O’Nolan’s comic inspiration that emerges from this scholarly engagement with his broader body of work underlines both the imperative and opportunity of reassessing O’Brien’s literary legacy. Challenging the critical standard of O’Brien as a provincial writer, these essays reveal his writing as a space that uniquely complicates the old lines between stay-at-home conservatism and international experimentalism. Renegotiating O’Brien’s place in the European Avant-Garde alongside tensions closer to home – Republicanism, the Gaelic tradition, the Dublin literary scene – the collection reveals as outdated prejudice the dismissal of his talent as a matter of localised interest. Finally, the contributors excavate O’Nolan’s oeuvre as fertile territory for a broad range of critical perspectives by confronting some of the more complex ideological positions tested in his writing. Employing perspectives from genetic criticism and cultural materialism to post-modernism and deconstruction, the essays gathered in this volume address with new critical rigour the author’s gender politics, his language politics, his parodies of nationalism, his ideology of science, and his treatment of the theme of justice.