French mechanical engineer Louis Réard introduced a design he named the `` bikini , '' taking the name from the Bikini Atoll in the Pacific Ocean , where , four days earlier , the United States had conducted its first peace-time nuclear weapons test , part of Operation Crossroads .
Réard named his swimsuit the `` bikini '' , taking the name from the Bikini Atoll , one of a series of islands in the South Pacific where testing on the new atomic bomb was occurring that summer .