A pea coat (or pea jacket, pilot jacket) is an outer coat, generally of a navy-colored heavy wool, originally worn by sailors of European and later American navies. Pea coats are characterized by broad lapels, double-breasted fronts, often large wooden or metal buttons, and vertical or slash pockets. References to the pea jacket appear in American newspapers at least as early as the 1720s, and modern renditions still maintain the original design and composition.

A bridge coat is a pea coat that extends to the thighs, and is a uniform exclusively for officers and Chief Petty Officers. The reefer is for officers only, and is identical to the basic design but usually has gold buttons and epaulettes.

Today the style is considered a classic, and pea coats are now worn by all manner of individuals. The style has evolved to the addition of hoods.

A few of the jackets seen on the street are genuine navy surplus; being a classic garment, it is frequently available from retailers, though often with small design changes that reflect the current fashion trends. The standard for historical pea coats was 30 ounces (approx. 850 g) wool, most often made of heavy Melton Cloth through the 1970s in the U.S. Navy. Presently coats are made from 22–32 oz (620–910 g) wool. While pea coats are offered in many colors by retailers, the U.S. Navy-issue pea coat is dark blue.

A pea is most commonly the small spherical seed or the seed-pod of the pod fruit Pisum sativum. Each pod contains several peas. Peapods are botanically a fruit, since they contain seeds developed from the ovary of a (pea) flower. However, peas are considered to be a vegetable in cooking. The name is also used to describe other edible seeds from the Fabaceae such as the pigeon pea (Cajanus cajan), the cowpea (Vigna unguiculata), and the seeds from several species of Lathyrus.

P. sativum is an annual plant, with a life cycle of one year. It is a cool season crop grown in many parts of the world; planting can take place from winter to early summer depending on location. The average pea weighs between 0.1 and 0.36 grams. The immature peas (and in snow peas the tender pod as well) are used as a vegetable, fresh, frozen or canned; varieties of the species typically called field peas are grown to produce dry peas like the split pea shelled from the matured pod. These are the basis of pease porridge and pea soup, staples of medieval cuisine; in Europe, consuming fresh immature green peas was an innovation of Early Modern cuisine.