Abstract: A triangular golf bag cooler that includes a triangular longitudinal cross-section configured to fit the cooler within an extant golf bag pocket; the triangular golf bag cooler having a gel layer disposed between an outer liner and an interior liner; said gel layer freezable with a high specific heat capacity to provide extended cooling to items stored within an interior cavity; a drain plug disposed in a first side to drain condensation and melt water from the interior cavity; the triangular golf bag cooler collapsible when empty for easy portage and storage; to provide ready access to food items proximal to the golfer's clubs when playing on a fairway.