Adhesive composition, adhesive sheet, and optical member

Provided are an adhesive composition, an adhesive sheet, and an optical member, the adhesive composition containing a (meth) acrylic polymer (A), a (meth) acrylic copolymer (B), and a crosslinking agent, the polymer (A) containing a monomer unit having a crosslinkable functional group and having a Tg of less than 0 DEG C; the copolymer (B) contains 0.1-10% by mass of a monomer unit having an organosiloxane skeleton and 25-45% by mass of a (meth) acrylic monomer unit having a Tg of-30 DEG C or more and less than 10 DEG C when made into a homopolymer and an Mw of 40,000-400,000 with respect to all structural units; the Mn of the monomer having the organosiloxane skeleton in the copolymer (B) is not less than 4000 but less than 20000, and the content of the copolymer (B) is 0.1-21 parts by mass per 100 parts by mass of the polymer (A). 本发明提供一种粘合剂组合物、粘合片和光学部件，上述粘合剂组合物含有(甲基)丙烯酸系聚合物(A)、(甲基)丙烯酸系共聚物(B)和交联剂，上述聚合物(A)含有具有交联性官能团的单体单元，且Tg小于0℃，上述共聚物(B)含有相对于全部结构单元为0.1～10质量％的具有有机硅氧烷骨架的单体单元和相对于全部结构单元为25～45质量％的制成均聚物时的Tg为-30℃以上