Thea may refer to:

• Thea (name), a given name
• Ancient Greek term for goddess, including an alternative spelling of Theia
• Thea, the former name of the tea plant genus, now included in Camellia
• Thea, a village in the municipal unit Messatida, Achaea, Greece
• Thea (award), the annual award from the Themed Entertainment Association
• Thea (New-Gen), a Marvel Comics New-Gen character
• Thea (TV series), a 1993 short-lived television series starring Thea Vidale and Brandy Norwood
• Tampa-Hillsborough Expressway Authority, a regional expressway authority based in Hillsborough County, Florida
• Another word for the mythological animal theow
• "Thea", a song by Goldfrapp from Tales of Us
• Theia (planet), a planet hypothesized to have collided with Earth 4.5 billion years ago to form the moon
• Thea, a video game series beginning with Thea: The Awakening