Hyperolius koehleri is a species of frog in the family Hyperoliidae. It is known from southeastern Nigeria, southern Cameroon, and northern Gabon. It is likely to also be found in Equatorial Guinea and the adjacent Republic of the Congo. Common name Koehler's green frog has been coined for it.
Hyperolius koehleri measure 26–29 mm (1.0–1.1 in) in snout–vent length, with the range 26–27 mm (1.0–1.1 in) indicated for adult males. The head is rather flat. The dorsum is grass green with diffuse red-brown spots and a chrome yellow dorsolateral stripe. Legs are somewhat lighter and more yellowish. Underside of limbs is pale green; feet and hands are yellow. Throat is turquoise, breast white, and abdomen translucent green. The eye is golden green or, in juveniles, reddish, and has horizontal pupil. Males have numerous black spines on flanks, underside of limbs and feet when in breeding condition.
The male advertisement call is a feeble, barely audible twittering or chirping. Females lay 40–60 eggs measuring 2–2.3 mm (0.079–0.091 in) in diameter. The tadpoles grow a maximum length of 39 mm (1.5 in).
