Lamb comes from sheep less than one year of age, and often as young as five to seven months. Special varieties include baby or hot house lamb, which is only six to ten weeks old, and French pré-salé lamb that is raised on salt meadows near the sea. Imported New Zealand lamb, fed on grass rather than grain, has a somewhat stronger taste. Most mutton sold in the United States comes from sheep between one and two years old. It has a more robust taste than lamb.

Lamb and mutton are available in many different cuts: legs, roasts, chops, stew meat, breasts, spareribs, foreshank, and ground lamb. Tender cuts come from the ribs and loin; tougher cuts from the legs and shoulders.