Said Musa was born in San Ignacio Cayo. After preliminary education in Belize (then British Honduras) he studied law at Manchester University in England, receiving an Honors Degree in Law in 1966. He returned to Belize the following year, serving as magistrate and crown council, and then going into private practice. He joined the pro-independence People's United Party (PUP), then under George Price, and served in Price's governments in various capacities, and helped draft Belize's new constitution in 1981.
Said Musa took over leadership of the PUP in 1996. He was elected Prime Minister of Belize in 1998 and again in 2003.