Thirty new species consisting of 24 poecilostomatoid and six siphonostomatoid copepods are described as associates of marine invertebrates from the Moluccas. New taxa in the order Poecilostomatoida are Amarda curvus n. sp., Anchimolgus gracilipes n. sp., A. partenuipes n. sp., A. parangensis n. sp., A. hastatus n. sp., Andrianellus papillipes n. sp., Exodontomolgus communis n. gen. n. sp., Jamescookina moluccensis n. sp., Odontomolgus flammeus n. sp., O. parvus n. sp., O. pavonus n. sp., Paranchimolgus parallelus n. gen. n. sp., and Scyphuliger karangmiensis n. sp. in the family Anchimolgidae; Enalcyonium circulatum n. sp. and E. ceramensis n. sp. in the family Lamippidae; Parastericola rimosus n. gen. n. sp. in the family Lichomolgidae; Pseudanthessius truncus n. sp. and P. planus n. sp. in the family Pseudanthessiidae; Acanthomolgus gomumuensis n. sp., A. dispadactylus n. sp., A. bandaensis n. sp., A. ambonensis n. sp., Kombia avitus n. sp. and Pionomolgus moluccensis n. sp. in the family Rhynchomolgiae. New taxa in the order Siphonostomatoida are Cryptopontius acutus n. sp. in the family Artotrogidae; Asteropontius fungicola n. sp., A. gonioporae n. sp., Collocheres humesi n. sp. and C. amicus n. sp. in the family Asterocheridae; and Molucomes ovatus n. gen. n. sp. in the family Stellicomitidae. Species new to the Moluccas and new host records are also included. Lists of 263 species of associated copepods known from the Moluccas and their 135 species of invertebrate hosts are provided.