Helicops hagmanni, also known commonly as Hagmann's keelback, is a species of snake in the subfamily Dipsadinae of the family Colubridae.

The species is native to the Amazon River basin in South America.

The specific name, hagmanni, is in honor of Swiss-Brazilian zoologist Gottfried A.

[2] H. hagmanni is found in Brazil, Colombia, Peru, and Venezuela.

[1] The preferred natural habitat of H. hagmanni is freshwater wetlands in forest, at altitudes below 250 m (820 ft).