Recent examinations of cucullanid nematodes (Cucullanidae) from marine fishes off New Caledonia, collected in the years 2004–2009, revealed the presence of the following five new species of Cucullanus Müller, 1777, all parasitic in Perciformes: Cucullanus variolae n. sp. from Variola louti (type host) and V. albimarginata (both Serranidae); Cucullanus acutospiculatus n. sp. from Caesio cuning (Caesionidae); Cucullanus diagrammae n. sp. from Diagramma pictum (Haemulidae); Cucullanus parapercidis n. sp. from Parapercis xanthozona (type host) and P. hexophtalma (both Pinguipedidae); and Cucullanus petterae n. sp. from Epinephelus merra (type host) and E. fasciatus (both Serranidae). An additional congeneric species, Cucullanus bioccai Orecchia et Paggi, 1987 was recorded from Mugil cephalus (Mugilidae, Mugiliformes) (first record in the Pacific Ocean) and Cucullanus sp. (only female) was found in Arothron manilensis (Tetraodontidae, Tetraodontiformes). Furthermore, two known cucullanid species, Dichelyne (Cucullanellus) branchiostegi (Yamaguti, 1941) in Branchiostegus wardi (Malacanthidae, Perciformes) (new host and geographical records) and Dichelyne (Cucullanellus) bodiani Moravec et Justine, 2019 in Bodianus busellatus (new host) and B. perditio (both Labridae, Perciformes), were found; Dichelyne (Cucullanellus) sp. (only females) coinfecting the latter host may represent an unknown species. Most species are described based on light and electron microscopical studies. The specimens described by Xu et al., 2017 as Cucullanus bourdini Petter et Le Bel, 1992 from Caesio xanthonota (Caesionidae) in the Taiwan Strait are considered to represent a new species, for which the name Cucullanus sinensis n. sp. is proposed.