Twenty-two species of Canthigaster (Tetraodontidae; Canthigasterinae), including seven which are described as new, are recognized from the tropical Indo-Pacific: C. amboinensis (widespread Indo-Pacific), C. bennetti (widespread Indo-W. Pacific), C. callisterna (New South Wales; Lord Howe, Norfolk, and Kermadec islands; northern New Zealand), C. compressa (E. Indies; Melanesia; Philippine Islands), C. coronata (widespread Indo-W. Pacific), C. epilampra (W. Pacific), C. inframacula n. sp. (Hawaiian Islands), C. investigatoris (Andaman Islands), C. jactator (Hawaiian Islands), C. janthinoptera (widespread Indo-W. Pacific), C. margaritata (Red Sea), C. marquesensis n. sp. (Marquesas Islands), C. natalensis (Mauritius; South Africa), C. ocellicincta n. sp. (Melanesia; Great Barrier Reef), C. punctatissima (eastern Pacific), C. pygmaea n. sp. (Red Sea), C. rapaensis n. sp. (Rapa), C. rivulata (widespread Indo-W. Pacific), C. smithae n.sp. (Mauritius, and South Africa), C. solandri (widespread Indo-W. Pacific), C. tyleri n. sp. (Indian Ocean), and C. valentini (widespread Indo-W. Pacific). Notes are included on the ecology and distribution, and food habit data are presented for five species. Tables of meristic and morphometric characters, colour illustrations of 20 species, black-and-white photographs of three species, synonymies, and a diagnosis or description for each species are included.