Mariette or Mariëtte may signify:

Family name

• Auguste Mariette (1821–1881), pioneering Egyptologist.
• Pierre-Jean Mariette (1694–1774), connoisseur and chronicler of artistic life in Paris

Given name

• Mariette Bosch (died 2001), South African murderer executed by Botswana
• Mariëtte Drewes (born 1967), Dutch chess player
• Mariëtte Hamer (born 1958), Dutch politician and trade union leader
• Mariette Hansson (born 1983), sometimes MaryJet or simply mononym Mariette, Swedish singer and songwriter
• Mariëtte Patijn (born 1966), Dutch politician

Others

• Mariette, a yacht built by Nathanael Greene Herreshoff in 1915