The generalized fractional integral operators are shown to be bounded from an Orlicz–Hardy space HnormalΦfalse(Rnfalse) to another Orlicz–Hardy space HnormalΨfalse(Rnfalse), where Φ and Ψ are generalized Young functions. The result extends the boundedness of the usual fractional integral operator Iα from Hpfalse(Rnfalse) to Hqfalse(Rnfalse) for α,p,q∈(0,∞) and −n/p+α=−n/q, which was proved by Stein and Weiss in 1960.