Nova Iguacu is a city in southeast Brazil in the Baixada Fluminense region of Rio de Janeiro state. It was the state's second largest city until Mesquita was split off, and now is the fourth largest after Sao Gonçalo and Duque de Caxias. It lies northwest of the city of Rio de Janeiro, on the limits of the metropolitan area. The current mayor is Sheila Gama (PDT). The city is the seat of the Roman Catholic Diocese of Nova Iguacu.