Helmut Clissman (11 May 1911 – 6 November 1997) was a German spy (Abwehr agent) during World War II.
He engineered the release of Frank Ryan from Spanish prison. Before World War 2 Clissmann was active in the German academic exchange service in Dublin. He was involved in both Operation Lobster and Operation Sea Eagle which were both failed operations with the intent of getting Clissmann into Ireland.
He became a businessman and set up an agency to import pharmaceutical products. He was also afounding member of what is now the Irish Pharmaceutical Healthcare Association and Amnesty International Ireland. St Killian's German school was co-founded by him and he was made its honorary president-for-life.
Clissmann was friends with fellow German spy Jupp Hoven. He married a Sligo woman Budge Mulcahy and had multiple children.