The works of the 17th-century mathematician Pierre de Fermat engendered many theorems. Fermat's theorem may refer to one of the following theorems:

• Fermat's Last Theorem, about integer solutions to aⁿ + bⁿ = cⁿ
• Fermat's little theorem, a property of prime numbers
• Fermat's theorem on sums of two squares, about primes expressible as a sum of squares
• Fermat's theorem (stationary points), about local maxima and minima of differentiable functions
• Fermat's principle, about the path taken by a ray of light
• Fermat polygonal number theorem, about expressing integers as a sum of polygonal numbers
• Fermat's right triangle theorem, about squares not being expressible as the difference of two fourth powers

• List of things named after Pierre de Fermat

This article includes a list of related items that share the same name (or similar names).
If an internal link incorrectly led you here, you may wish to change the link to point directly to the intended article.