Leptophilypnion is a genus of tiny fishes in the family Eleotridae endemic to the Amazon Basin in South America.

At less than 1 cm (0.4 in) in standard length they are the smallest sleeper gobies and among the smallest fish.

[2] The larger Microphilypnus sleeper gobies are also found in the Amazon,[3] and sometimes occur together with Leptophilypnion.

[2] The bottom-dwelling Leptophilypnion are typically found in shallow, stagnant or slow-flowing water among soft debris, leaf-litter or water plants.

[2] The recognized species in this genus are:[2]