This is an annotated list of important diamond business magnates. It is in alphabetical order based on last name.

This list is incomplete; you can help by adding missing items. (June 2023)

• Barney Barnato (1851–1897), British Randlord and diamond magnate
• Alfred Beit (1853–1906), Anglo-German gold and diamond magnate
• Thomas Cullinan (diamond magnate) (1862–1936), South African diamond magnate.
• David Harris (South African businessman) (1852–1942), South African soldier, diamond magnate, and legislator
• John Dale Lace (1859–1937), South African gold and diamond magnate.
• Lev Avnerovich Leviev (born 1956), Israeli diamond magnate, investor, and philanthropist
• William McHardy (diamond magnate) (1846–1913), Scottish-South African diamond magnate
• Cecil Rhodes (1853–1902), British mining magnate and politician
• Maurice Tempelsman (born 1929), Belgian-American businessman, a diamond magnate, and merchant
• Sir Harold Wernher, 3rd Baronet (1893–1973), British military officer and diamond magnate
• Sir Julius Wernher, 1st Baronet (1850–1912), German-born Randlord, diamond magnate, and art collector