A shopping cart (American English), trolley (British English, Australian English), or buggy (Southern American English, Appalachian English), also known by a variety of other names, is a wheeled cart supplied by a shop or store, especially supermarkets, for use by customers inside the premises for transport of merchandise as they move around the premises, while shopping, prior to heading to the checkout counter, cashiers or tills. Increasing the amount of goods a shopper can collect increases the quantities they are likely to purchase in a single trip, boosting store profitability.

In many cases customers can then also use the cart to transport their purchased goods to their vehicles, but some carts are designed to prevent them from leaving either the store or the designated parking area by magnetically locking the wheels. In many places in the United States, Canada and the United Kingdom, customers are encouraged to leave the carts in designated areas within the parking lot, and store employees will return the carts to the entrances. In some areas carts are connected by locking mechanisms that require the insertion of a coin or token to release an individual cart. Returning the cart to its designated area releases the coin to the customer.

Studies have shown that it is advisable for shoppers to sanitize the handles and basket areas prior to handling them or filling them with groceries due to high levels of bacteria that typically live on shopping carts. This is due to the carts having a high level of exposure to the skin flora of previous users.