Specimens of a new soritid foraminifer were collected from Bird Island, of the Lizard Island Group, Great Barrier Reef, Australia. Differences in aperture arrangement, shape, and number, and in internal test morphology are reported which distinguish the Bird Island specimens from previously described soritines. The analysis supports the establishment of a new species that we name Amphisorus sauronesensis. Molecular systematic comparison suggests that the new species is closest to Amphisorus hemprichii (Ehrenberg 1839) and supports the placement of the new species in the genus Amphisorus (Quoy and Gaimard 1830). Cytological investigations indicate the presence of symbiotic dinoflagellates throughout A. sauronesensis sp. nov., with the highest concentration of symbionts located in the intermediate chambers.