We present a species checklist, characterizing the ichthyofaunal composition of four coastal archipelagos in waters off the metropolitan area of Rio de Janeiro, Brazil. Data were obtained from ~120 h of underwater observations, published and unpublished information, including new species records. A total of 197 fish species (78 new records), belonging to 130 genera and 61 families, were observed. The family Carangidae (17) dominated in number of species, followed by Labridae and Serranidae (10 each), Epinephelidae and Scaridae (9 each). Most species are distributed along the tropical western Atlantic (51.8%) or on both sides of the Atlantic Ocean (20.5%). A minor part is endemic to Brazil (9.7%) or range to temperate rocky reefs of Patagonia (6.7%). Fourteen species are threatened, according to the IUCN, and listed under the Brazilian Ministry of the Environment red list (6.6%). Despite an increment of fish species listed herein, and the recent establishment/creation of a Marine Protected Area (Monumento Natural das Ilhas Cagarras—MoNa Cagarras), research efforts are clearly needed along these archipelagos, as nearshore environmental threats increase due to lack of regulatory practices.