This chapter describes the characteristics of a sheep’s carcass and explains the principles of carcass composition (the weight or proportion of muscle, fat and bone in the carcass). Understanding carcass characteristics and finding techniques for altering the characteristics are important for maximising returns to the producer, since carcass traits can both inform breeding objectives and moderate meat quality. This chapter examines the factors that influence a carcass’ dressing-out percentage (the relative proportions of carcass and non-carcass components in an animal’s body), carcass composition, distribution and partitioning of tissues within the carcass and carcass shape. The chapter evaluates the contribution that understanding carcass characteristics can make to meat production and considers directions for future research.