A magnetoresistive effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a nonmagnetic layer, and at least one of a first nonmagnetic insertion layer provided directly on a lower surface of the nonmagnetic layer and a second nonmagnetic insertion layer provided directly on an upper surface of the nonmagnetic layer. The first nonmagnetic insertion layer and the second nonmagnetic insertion layer include an Ag alloy represented by General Formula (1): AgγX1-γ where X indicates one element selected from the group consisting of Al, Cu, Ga, Ge, As, Y, La, Sm, Yb, and Pt, and 0