Mata Nui may refer to:

• Mata Nui, a character in the Lego Bionicle series
• Mata Nui, an island in the Lego Bionicle series
• Mata Nui Online Game
• The sequel to the game of the same name, Mata Nui Online Game II

• Rhesus Factor (Rh factor)
• Rhesus Macaque Monkey
• Rhesus macaques
• Rhesus monkeys
• Rhesus negative
• Rhesus (play)
• Rhesus positive
• Rheta Childe Dorr
• Rheta DeVries
• Rheta Dorr
• Rheta Johnson
• Rhetenor
• Rheteosaurus
• Rhetian Alps
• Rhetorica
• Rhetorica ad herennium
• Rhetorical analysis
• Rhetorical devices
• Rhetorically
• Rhetorical modes
• Rhetorical Question
• Rhetorical reason
• Rhetorical Reason
• Rhetorical stance
• Rhetorical Tautology