The Red Emperor or Red Deity (赤帝 Chìdì) was a legendary ancient Chinese ruler in pre-dynastic times.

Red Emperor or red emperor may also refer to:

• Emperor (grape), a red grape variety also known as Red Emperor
• Lutjanus sebae, a species of fish, also known as red emperor
• Mao Zedong (1893–1976), Chairman of the Chinese Communist Party, sometimes called the Red Emperor
• "Red Emperor", a cultivar of the tulip Tulipa fosteriana