Born in Milan in 1924, de Giorgio attended the Carlo Pisacane School in Milan and Flores College, Valletta. After obtaining the Senior Oxford School certificate, he was employed as librarian by the British Institute in Valletta (1941-42). During World War II he served as lieutenant in the 3rd LAA Regiment with the RMA.
In 1945 de Giorgio established Maurice de Giorgio Ltd. to import building material. He also became a partner in Home Furnishing Ltd., a bedding manufacturing company, and Venetian Blinds (Malta) Ltd. In 1961 he merged with Joinwell Ltd. as shareholder and director. Between 1961 and 1985 he was hon. secretary and council member of the Federation of Malta industries, hon. secretary and executive council member of the Malta Trade Fair Corporation, member of the hoard which set up and review the reorganization of the Malta Milk Marketing Undertaking, director of the Aids to Industries Board, and founder director of the Malta Development Corporation.
de Giorgio was also involved in cultural activities and was member of the Manoel Theatre Management Committee. In 1992 he was elected chairman of the Fondazzjoni Patrimonju Malti. In 1995 he was invested with the Order of Merit of the Republic of Malta for services rendered to Maltese culture.