Disclosed is an oxygen-absorbing resin which exhibits excellent oxygen absorption performance even in the absence of a transition metal catalyst. Specifically disclosed is an oxygen-absorbing resin which is composed of a copolyester obtained by copolymerizing at least the following monomers (A)-(C). Monomer (A): a dicarboxylic acid or a derivative thereof having a carbon atom bonded to both the structures (a) and (b) below and also bonded to one or two hydrogen atoms, wherein the carbon atom is contained in an alicyclic structure (a) a carbon-carbon double bond group (b) any one of a functional group containing a heteroatom or a linking group derived from such a functional group, a carbon-carbon double bond group and an aromatic ring; Monomer (B): at least one selected from the group consisting of a dicarboxylic acid having an aromatic ring or a derivative thereof, and a hydroxycarboxylic acid having an aromatic ring or a derivative thereof; Monomer (C): a diol.