Provided is a resin composition including a resin containing a polymer, a hygroscopic particle, and an organic solvent-soluble dispersant. Preferably the ratio of the dispersant relative to 100 parts by weight of the hygroscopic particle is 0.1 part by weight or more and 1000 parts by weight or less, and the absolute value of the difference in refractive index between the resin and the hygroscopic particle is 0.05 or less. Also provided are a resin film formed by molding the resin composition into a film shape, and an organic electroluminescent device including the resin film.