Fascia is a specialized connective tissue layer which surrounds muscles, bones, and joints, providing support and protection and giving structure to the body. It consists of two layers: the superficial fascia and the deep fascia.

Superficial Fascia is located directly beneath the subcutis of the skin. It functions in storing fat and water and also provides passageways for nerves and blood vessels. In some areas of the body, it also houses a layer of skeletal muscle, allowing for movement of the skin.

Deep Fascia is located directly beneath the layer of superficial fascia. It functions in aiding muscle movements and, like the superficial fascia, provides passageways for nerves and blood vessels. In some areas of the body, it also provides an attachment site for muscles and acts as a cushioning layer between muscles.

Fascia can also mean a line parallel to the body on the wing of Lepidoptera species.

Fascia is also a term used in retailing, to refer to retail store brand names. Technically it refers to the "flat surface above a shop window" (Collins Dictionary), where the shop/store name is often located. A retail company may operate several fascia, such as Woolworths or Progressive Enterprises.