A curable composition for a denture base is provided which comprises a paste-like composition containing (A) (meth)acrylic monomers, (B) a monomer-absorbing porous organic cross-linked polymer which can absorb the (A) (meth)acrylic monomers, and (C) a polymerization initiator selected from a photopolymerization initiator and a thermal polymerization initiator, wherein the content of (B) the monomer-absorbing porous organic cross-linked polymer is 20-80 parts by mass per 100 parts by mass of the (A) (meth)acrylic monomers, and the absorption amount: RAb={(g−A)/(g−B)}, measured in accordance with JIS K5101-13-1:2004, and defined by the amount of (A) (meth)acrylic monomers: g−A (unit: g) absorbed per unit amount of (B) the monomer-absorbing porous organic cross-linked polymer: g−B (unit: g) is greater than or equal to 1.5.