<p>The problem of sum-frequency generation by two elliptically polarized plane waves in a thin optically nonlinear surface layer of a dielectric spheroidal particle was solved in the generalized Rayleigh–Gans–Debye approximation. Formulas for calculating the components of the electric intensity vector of the generated radiation in the far zone were obtained for two cases: the spheroid elongated and compressed along the symmetry axis. The most general form of the nonlinear dielectric susceptibility tensor containing four non-chiral and three chiral independent components was considered. A detailed description of methods for calculating integrals over the surface of the spheroid of tensor quantities encountered in problems of nonlinear generation in the surface layers of dielectric particles was given.</p>