A wavelength-converting resin composition for a photovoltaic cell, comprising: a fluorescent substance having a maximum absorption wavelength in an absorbance spectrum of which being λmax (nm); resin particles; and a dispersion medium resin, wherein a value of A1 (λ), which is represented by the following Equation 1, at the maximum absorption wavelength λmax (nm) is 3.0×10−4 (O.D./μm) or less in a case in which: an intensity of transmitted light that is obtained as a result of incident light having a light intensity of I0 (λ) at a wavelength λ (nm) having passed through a resin film in a thickness direction of the resin film, the resin film being formed from the resin composition and having a thickness of t (μm), is defined as I (λ); and an intensity of transmitted light that is obtained as a result of the incident light having passed through a reference resin film in a thickness direction of the reference resin film, the reference resin film being formed from a reference resin composition obtained by excluding the fluorescent substance and the resin particles from the resin composition, and having a thickness of tref (μm), is defined as Iref (λ). A1(λ)={log(I0(λ)/I(λ))}/t−log {(I0(λ)/Iref(λ))}/tref  Equation 1