A poly(glycolic acid)-containing resin composition includes a poly(glycolic acid), a zinc-containing ionomer (Zn ionomer), and an ethylene-based terpolymer. A film including the poly(glycolic acid)-containing resin composition is also provided. The poly(glycolic acid)-containing resin composition and the film can be widely applied in the field of green technologies, such as a biodegradable resin, a biodegradable food packaging film, a biodegradable sanitary product, and other biodegradable plastics.