In mathematics, Suslin's theorem may refer to:
- The Quillen–Suslin theorem (formerly the Serre conjecture), due to Andrei Suslin.
- Any of several theorems about analytic sets due to Mikhail Yakovlevich Suslin; in particular:
- There is an analytic subset of the reals that is not Borel
- An analytic set whose complement is also analytic is a Borel set, a special case of the Lusin separation theorem
- Any analytic set in Rn is the projection of a Borel set in Rn+1
- Analytic sets can be constructed using the Suslin operation