Tun Datu Haji Mustapha bin Datu Harun, or Tun Mustapha for short (31 July 1918 – 2 January 1995), was the first governor of the Malaysian state of Sabah.
He was also the third chief minister of the state from 1967 to 1975, and was the president for the political party United Sabah National Organisation (USNO).
He is considered by some to be one of the founding leaders of Sabah and was an important party in the negotiations leading to the formation of Malaysia on 16 September 1963.He is known to some as the "father of Sabah's independence" (Bapa Kemerdekaan Sabah) and also the "father of Sabah's development" (Bapa Pembangunan Sabah).
However, he is also considered by many Sabahan opposition leaders who later formed the new party BERJAYA as a dictator and alleged to misappropriated huge sums of money from the state's coffers (primarily through timber concessions) to support his lavish lifestyle.