An air raid shelter, also known as bomb shelter, is a protection structure for the civilian population and military personnel against possible enemy attacks (bombing) from the air. They are similar in some ways to bunkers, although they are not designed to protect against ground attacks (some have been successfully used as ground defensive structures).

These shelters were built to protect against enemy air raids, however other existing structures with other functions were suitable to safeguard people during attacks; underground stations, tunnels, basements of large establishments and bridges. A widely used homemade shelter was known as the "Anderson Shelters", built with corrugated steel sheets in the garden.