Captain David O'Keefe is a character based on the real-life 18th-century American who introduced modern agricultural methods to the South Seas. Lest you think that His Majesty O'Keefe is merely a feature-length version of your local TV station's agribusiness report, be advised that O'Keefe is played by Burt Lancaster, his biceps fairly bursting out of his period costume. Lancaster's version of O'Keefe is a garrulous mercenary who agrees to help the native farmers in exchange for a fortune in Copra, an oil-yielding form of coconut pulp. In addition to Copra, the island is rich with Rice--Joan Rice, that is, who portrays the dusky native girl with whom O'Keefe dallies. His Majesty O'Keefe arrives at its anticipated slam-bang finale when O'Keefe does battle with greedy, usurping white traders. The film was freely adapted from the popular novel by Lawrence Kingman and Gerald Green.
~ Hal Erickson, All Movie Guide