We describe a new species of acanthocephalan from the reef fish Kyphosus bigibbus Lacepède, Kyphosus sydneyanus (Günther), and Kyphosus vaigiensis (Quoy and Gaimardi) from Heron Island, Queensland; Ningaloo Reef, Western Australia; and Moorea, French Polynesia, respectively. Filisoma filiformis n. sp. is differentiated primarily from other species by its long, slender proboscis, with 16–18 longitudinal rows of 42–48 hooks. The wide distribution and multiple host species of F. filiformis suggest that it could be found in other localities around the Indo-Pacific region where kyphosid fish occur. The differing patterns of host range and geographic distribution within the genus Filisoma are discussed.