Pattypan Squash, or button squash in Australian English, is a summer squash notable for its small size, round and shallow shape, and scalloped edges, somewhat resembling a small toy top. The name "pattypan" derives from "a pan for baking a patty." Its French name, "pâtisson," derives from a Provençal word for a cake made in a scalloped mould. The pattypan squash is also know as "cymling", "scallop squash", "custard marrow", or "custard squash".

Pattypan comes in yellow, green, and white varieties. The squash is most tender when relatively immature; it is generally served when it is no more than two to three inches in diameter. In fine cuisine, its tender flesh is sometimes scooped out and mixed with flavorings such as garlic prior to reinsertion; the scooped-out husk of a pattypan also is sometimes used as a decorative container for other foods. Pattypan is a good source of magnesium, niacin, and vitamins A and C. One cup contains approximately 20 to 30 calories and no fat.