Three cultured orange-spotted grouper, Epinephelus coioides sizes 22.1 to 24.5-cm-long from the Setiu Wetland were examined for fish parasites, in November 2015. One individual from 3 adult E. coioides harboured a myxosporean infection in its gall bladder. In this study, Ceratomyxa sp. specimens were studied under the phase contrast of light compound microscope. The myxosporean is here identified as Ceratomyxa Thélohan, 1892, diagnosed based on the elongated spores from valvular view whereas crescentshaped from sutural view. Dimensions of spores were found to be 4.1 × 18.2 μm. The spores have two equal-sized pyriform polar capsules 1.7 × 1.4 μm, the polar filaments turns not detected. This is the first record of Ceratomyxa Thélohan, 1892 from the gall bladder of orange spotted grouper, Epinephelus coioides from Setiu Wetlands, Terengganu.