Welsh rarebit or Welsh rabbit is a dish of hot cheese sauce served on toasted bread. The original 18th-century name of the dish was the jocular "Welsh rabbit", which was later reinterpreted as "rarebit", as the dish contains no rabbit. Variants include English rabbit, Scotch rabbit, buck rabbit, golden buck, and blushing bunny.

Cheese sauce is a sauce made with cheese or processed cheese as a primary ingredient. Sometimes dried cheese or cheese powder is used. Several varieties exist and it has many various culinary uses. Mass-produced commercial cheese sauces are also made by various companies, in both liquid and dry forms. These prepared sauces are used by consumers and restaurants, and commercial formulations are used in the production of various prepared foods, such as macaroni and cheese mixes and frozen meals.