Abstract: A collapsible child seat assembly for a shopping cart has a plastic seat panel and a plastic leg opening cover, both of which are pivotally mounted on a horizontal hinge wire that itself is fixedly mounted on a swingable rear gate of the cart. The forward edge of the seat panel is slidably mounted to a seat back pivotally attached to the rear gate. The rear edges of the seat panel and leg opening cover have interdigitated hinge extensions forming slots that accept therein the horizontal hinge wire for pivotal motion thereon. The hinge wire has protuberances corresponding to the locations of the hinge extensions of the leg opening cover. These protuberances cooperate with cantilevered leaf springs extending into the slots of the hinge extensions of the leg opening cover to frictionally retain the leg opening cover in its upright position covering the leg openings until it is manually folded against the seat panel.