Resin composition and molded resin object

A resin composition, comprising:

• a cellulose acylate (A) including at least one type selected from cellulose acetate propionate and cellulose acetate butyrate,
• a polylactic acid (B),
• an ester compound (C) having a molecular weight of 250 or more and 2,000 or less, and
• a polymer with a core-shell structure (D) having a core layer and a shell layer including a (meth)acrylic polymer on the surface of the core layer, wherein:
• the ratio ((B)/(A)) of the mass of the polylactic acid (B) to the mass of the cellulose acylate (A) is 0.03 or more and 0.5 or less,
• the ratio ((C)/(A)) of the mass of the ester compound (C) to the mass of the cellulose acylate (A) is 0.03 or more and 0.15 or less, and
• the ratio ((D)/(A)) of the mass of the polymer with a core-shell structure (D) to the mass of the cellulose acylate (A) is 0.01 or more and 0.1 or less.