Ammonia, Brünnich, 1771, is amongst the most commonly found and widely distributed benthic foraminiferal genus inhabiting shallow-marine and estuarine environments worldwide. In this study, we describe Ammonia nigami sp. nov., a new living multi-chambered rotaliid benthic foraminifer from the Chandipur coast, Odisha (Bay of Bengal). The new species has a test of moderate size (0.5–0.7 mm diameter), 2–2.5 whorls, 8–10 trapezoidal-shaped chambers in the final whorl, inflated trochospiral biconvex test, and one needle-like spine of variable length on the periphery of each chamber. We have measured morphological characters of the test to discriminate the new species from other described Ammonia. Phylogenetic analysis, using partial small subunit rRNA gene sequences, shows that Ammonia nigami branches in a clade with A. bradyi and Ammonia sp. O. The species has been sampled from the east coast of India, Bay of Bengal, and might be locally restricted, although more sampling from different areas will be necessary to confirm the finding.