Dennis Howard Marks (born 13 August 1945 in Kenfig Hill, near Bridgend, Glamorgan, Wales) is a former teacher, drug smuggler and author who achieved notoriety as an international hashish smuggler through high-profile court cases, supposed connections with groups such as the IRA, and the Mafia, and his eventual conviction at the hands of the American Drug Enforcement Administration. At the height of his drug career, he was said to have controlled 10% of the world's hashish trade.
He spent seven years imprisoned in the Federal Correctional Complex, Terre Haute, Indiana. During his smuggling career, he claims not to have used violence and to have refused to deal with hard drugs. Both he and his now ex-wife Judy Marks were extradited from Majorca, Spain to Florida. They have three children together; Amber, Francesca and Patrick. He also has an older daughter, Myfanwy, from a 5 year relationship with Rosie Lewis.