The antifouling coating composition according to the present invention includes a silylacrylic copolymer including a structural unit (1) derived from triisopropylsilyl methacrylate (i), a structural unit (2) derived from triisopropylsilyl acrylate (ii) and a structural unit (3) derived from a polymerizable monomer having a polymerizable double bond (iii), which excludes the above (i) and (ii), the silylacrylic copolymer satisfies specific requirements. Thus, an antifouling coating composition that is excellent in long-term storage stability and gives a coating film excellent in long-term antifouling properties and long-term water resistance can be provided.