Abstract. The ring of integer-valued polynomials on an arbitrary integral domain is well-studied. In this paper we initiate and provide motivation for the study of integer-valued polynomials on commutative rings and modules. Several examples are computed, including the integer-valued polynomials over the ring R[T1, . . . , Tn]/(T1 (T1 − r1), . . . , Tn(Tn − rn)) for any commutative ring R and any elements r1, . . . , rn of R, as well as the integer-valued polynomials over the Nagata idealization R(+)M of M over R, where M is an R-module such that every non-zerodivisor on M is a non-zerodivisor of R.