Provided is a curable composition containing a polymerizable monomer (A), an organic-inorganic composite filler (B), and a polymerization initiator (C), wherein the organic-inorganic composite filler (B) includes an organic resin matrix (b1) and a spherical inorganic filler (b2) having an average primary particle size of 230-1000 nm, 90% or more of the number of individual particles constituting the spherical inorganic filler (b2) are present in a range of 5% greater or less than the average primary particle size, and the curable composition satisfies the following formulas (1) and (2): nP <; nFb2 (formula 1) and nMb1 <; nFb2 (formula 2). In the formulas, nP represents the refractive index of the polymer of the polymerizable monomer (A) at 25°C, nFb2 represents the refractive index of the spherical inorganic filler (b2) at 25°C, and nMb1 represents the refractive index of the organic resin matrix (b1) at 25°C.