Thia is a genus of crabs

Thia may also refer to:

• Tegeticula, a prodoxid moth genus invalidly described as Thia by H. Edwards in 1888
• 405 Thia, an asteroid
• Thia Megia (born 1995), a contestant in the 10th season of American Idol
• Henry Thia (born 1952), Singaporean actor and comedian
• Shawn Thia (born 1995), Singaporean actor
• Thia, a character in Predator: Badlands

• Thea (disambiguation)
• Theia (disambiguation)