Final Theory may refer to:

• Theory of everything, a putative theory in physics
• Final Theory (novel), a 2008 science fiction novel by Mark Alpert

• Bishop's hat
• Bishops Hatfield,
• Bishop Short
• Bishop's House
• Bishops House
• Bishop's House, Birmingham
• Bishop's House (disambiguation)
• Bishops House, Perth
• Bishop's House, Thursday Island
• Bishop's House, Toowoomba
• Bishop Simms
• Bishop Simon Brute College Seminary
• Bishop Simon Bruté College Seminary
• Bishop's Lynn (UK Parliament constituency)
• Bishop's messenger
• Bishop's Messengers
• Bishop's mitre
• Bishop's Mitre (disambiguation)
• Bishop's money
• Bishop's Move
• Bishop's Norton
• Bishop's Norton, Gloucestershire
• Bishops of Acre
• Bishops of Agde
• Bishops of Agrigento