In algebraic geometry, a relative cycle is a type of algebraic cycle on a scheme. In particular, let X {\displaystyle X} be a scheme of finite type over a Noetherian scheme S {\displaystyle S}, so that X → S {\displaystyle X\rightarrow S}. Then a relative cycle is a cycle on X {\displaystyle X} which lies over the generic points of S {\displaystyle S}, such that the cycle has a well-defined specialization to any fiber of the projection X → S {\displaystyle X\rightarrow S}.(Voevodsky & Suslin 2000)

The notion was introduced by Andrei Suslin and Vladimir Voevodsky in 2000; the authors were motivated to overcome some of the deficiencies of sheaves with transfers.