An annotated checklist of scleractinian and hydrozoan corals that have been collected from the Mariana Islands archipelago is presented for a special volume of Micronesica titled "The Marine Biodiversity of Guam and the Marianas." A total of 403 scleractinian and hydrozoan coral species representing 21 families and 108 genera are listed for the Mariana Islands. A total of 112 species are listed that have not been previously recorded from the Mariana Islands. Twelve of the new listings are azooxanthellate hydrozoan species, and of the 100 new scleractinians listed 25 are zooxanthellate species and 75 are azooxanthellate species. Each listed species is accompanied with a literature citation that provides a photographic illustration and a representative voucher specimen, or the authors field collection note citation and a representative voucher specimen when a published record was not available.
