Mohamed Ghassan Maumoon (; born 20 June 1980) is a Maldivian politician who served as the Minister of Defence of the Maldives since 2023. He has held many ministerial positions in past administrations of the Maldivian government. He was a Member of the People's Majlis for the Guraidhoo constituency. He served as vice president of the Progressive Party of Maldives from 2019 until its dissolution in 2025. He's been serving as the vice president of the People's National Congress since 2025.
Ghassan studied Molecular Biology & Biomedical Sciences Research at King's College London.
Ghassan has held many positions in the government. His first ministerial position was as State Minister for Human Resources, Youth and Sports during the presidency of Mohamed Waheed Hassan Manik. Later during the presidency of his uncle, Abdulla Yameen Abdul Gayoom, he was the State Minister for Youth and Sports. He was then later the State Minister at The President's Office and then the Minister of State for Social Affairs. He was also the Member of parliament of the 19th Session of the People's Majlis for the Guraidhoo Constituency.
Ghassan is the son and youngest child of the former president, Maumoon Abdul Gayoom and former first lady, Nasreena Ibrahim. His father was the longest serving president of the Maldives. Nasreena Ibrahim was the only first lady to give birth while in post. He was born in Machchangolhi, in Malé.