Diamantina may refer to:

• Diamantina Bowen (1833–1893), grande dame of Queensland and the wife of Sir George Bowen, the first Governor of Queensland.
• Diamantina Cocktail, 1976 album by Little River Band
• Diamantina National Park, Queensland
• Diamantina River, a river in Queensland and South Australia
• HMAS Diamantina, two ships in the Royal Australian Navy
• Shire of Diamantina, a local government area in Queensland

• Chapada Diamantina, a region of Bahia state
• Diamantina, Minas Gerais, a municipality and UNESCO World Heritage Site

• Diamantina fracture zone, Indian Ocean trench
  • Diamantina Deep

• Diamantina (plant), a genus of plants in the family Podostemaceae

• Diamantina, a fictional island in the Indian Ocean, in the animated television series Noah's Island