The present invention discloses a resin composition and a prepreg produced using the resin composition. The resin composition comprises, as essential components: 100 parts by mass of a component (A) which is an epoxy resin; 41 to 80 parts by mass of a component (B) which is thermoplastic resin particles; and 20 to 50 parts by mass (in terms of diaminodiphenylsulfone) of a component (C) which is diaminodiphenylsulfone microencapsulated with a coating agent. The thermoplastic resin particles (B) comprise at least thermoplastic resin particles (B1) having an average particle diameter of 1 to 50 μm and thermoplastic resin particles (B2) having an average particle diameter of 2 to 100 μm at a mass ratio of 3:1 to 1:3. The average particle diameter ratio D2/D1 of the average particle diameter D2 of the thermoplastic resin particles (B2) to the average particle diameter D1 of the thermoplastic resin particles (B1) is 2 or more.