These data describe the species abundance, size distributions, and habitat associations of roving herbivorous fishes (fishes belonging to the families, Acanthuridae, Scaridae, and Siganidae) found in different habitats in the lagoon and forereef on the north shore of Moorea. Adult fishes and large juveniles were counted (and their size estimated) by a SCUBA diver or snorkeler on thirty-four 50 m by 5 m wide transects. After counting large fishes, the entire transect was swam a second time, with the diver looking exclusively for small juvenile fishes on a 1 m swath. In addition to recording the species identity and estimated size of each juvenile encountered, the diver also recorded the particular microhabitat each individual or group of individuals was associated with. Finally, to quantify the relative availability of different types of microhabitat, the diver conducted point contacts where the primary benthic substrate was identified at regular (1 m) intervals on the same transect. This material is based upon work supported by the U.S. National Science Foundation under Grant No. OCE 16-37396 (and earlier awards) as well as a generous gift from the Gordon and Betty Moore Foundation. Research was completed under permits issued by the French Polynesian Government (Délégation à la Recherche) and the Haut-commissariat de la République en Polynésie Francaise (DTRT) (Protocole d'Accueil 2005-2018). This work represents a contribution of the Moorea Coral Reef (MCR) LTER Site.