A gate-and-seat assembly for a shopping cart includes a gate, a backrest, and a seat. The gate has a first end pivotally mountable to a rear portion of a shopping cart. The backrest includes a back support and a pair of legs with the back support defining a slot. The pair of legs extends from the back support and is pivotally mounted to a lower portion of the gate to enable pivotal movement of the backrest relative to the gate. The seat is pivotally mounted to the gate via at least one pivot mechanism and slidably extends through the slot of the back support. The seat includes a pair of ears extending laterally outward from the seat in opposite directions with each respective ear being releasably engageable relative to a rear surface of the back support of the backrest. The entire gate-and-seat assembly is made entirely from a plastic material. The seat is pivotally movable from a seating position to a collapsed position upon pivotal movement of the backrest relative to and toward the gate wherein the seat slidably moves through the slot of the back support and pivots downward toward the gate until both the seat and the back support are collapsed against the gate with the back support being spaced vertically above the seat.