Villegagnon Island (former Serigipe Island - original Portuguese: Ilha de Villegagnon - also known in English as: Villegaignon Island, Island of Villegagnon or Island of Villegaignon) is located near the mouth of the large Guanabara Bay, in the city of Rio de Janeiro, Brazil.

The island's name was given in honor of its first occupier, the French admiral Nicolas Durand de Villegaignon, whose troops occupied the Island in 1555, consequently, building Fort Coligny on the island when attempting to establish the France Antarctique colony. Actually the first Portuguese feitoria was located here. It was set up by the second voyage of Vespucci to Brazil. (The author is not an expert in Brazilian history, sadly enough)

With the arrival of more Portuguese troops from the São Vicente Capitania on March 15, 1560, Villegagnon Island became the stage for the attack from the Portuguese army commanded by Mem de Sá who deployed his troops on the Island. Two days later the French abandoned the fort looking for refuge with the Tamoios, a native tribe from Brazil. The fort was destroyed and on March 17, 1560 the first Portuguese mass was celebrated on the Island.