A gas barrier laminate comprising: a plastic substrate (I); a gas barrier layer (II) formed from a gas barrier layer-forming coating material (C) containing a polyalcohol-based polymer (A) and a polycarboxylic acid-based polymer (B); an overcoat layer (III) formed from an overcoat layer-forming coating material (F) containing at least one of a monovalent metal compound (D) and a bivalent or higher metal compound (E); and a top coat layer (IV) formed from a top coat layer-forming coating material (G); wherein the gas barrier layer (II) is laminated to the plastic substrate (I), either directly or with an anchor coat layer disposed therebetween, the overcoat layer (III) is laminated on top of the gas barrier layer (II), and the top coat layer (IV) is formed on top of the overcoat layer (III).