Imperator is a title used in the Roman Republic.

Imperator may also refer to:

• Imperator (ship), a German ocean liner
• Imperator (fungus), a genus of bolete mushroom
• Boa constrictor imperator, a subspecies of boa constrictor
• Pavo muticus imperator (Imperator, Indo-Chinese green peafowl, or dragonbird), a subspecies of the endangered green peafowl
• a title used in occult societies, such as AMORC, Confraternity of the Rose Cross, or FUDOSI
• a title used in Saga of the Skolian Empire by science fiction author Catherine Asaro
• Imperator Titan, a war machine in the fictional universe of Warhammer 40,000
  • Ave Imperator, a proclamation of loyalty to the Immortal God-Emperor of Mankind in Warhammer 40,000
• Imperator: Rome, a video game by Paradox Development Studio
• Imperator (horse)
• In the tabletop role-playing game Nobilis, Imperator is the term given for the god-like beings that empower the titular player characters.