A captive specimen of Meller's chameleon, Trioceros melleri (Gray), originally from Tanzania and housed at the Oklahoma City Zoological Park Herpetarium, Oklahoma County, Oklahoma, was found to be passing an undescribed species of Choleoeimeria in its feces. Oocysts of Choleoeimeria steveuptoni n. sp. were cylindroidal, 38.5 × 17.8 (36–42 × 17–19) µm with a bilayered wall and a shape index (length/width) of 2.2. A micropyle and oocyst residuum were absent, but a fragmented polar granule was often present. Ovoidal sporocysts were composed of 2 valves joined by a suture and measured 11.3 × 9.1 (11–12 × 9–10) µm; shape index of 1.3. Stieda, sub-Stieda, and para-Stieda bodies were absent. The sporocyst residuum consists of multiple globules dispersed along the perimeter of the sporocyst and between sporozoites. Sporozoites were elongate, 13.1 × 2.9 (12–15 × 2.6–3.2) µm with an elongate posterior refractile body. The new species represents the second coccidian documented from this lizard.