The Florentino Ameghino Dam (Dique Florentino Ameghino) is a gravity dam in Chubut Province, Patagonia, Argentina, 140 kilometres (87 mi) west of the city of Trelew.

The dam also protects the towns in the lower Chubut River valley from flooding.

The Florentino Ameghino is located on the Chubut River, which originates from snowmelt in the Andes.

Adjacent to the dam is a town with approximately 200 residents called Villa Dique Florentino Ameghino.

The dam takes its name from Florentino Ameghino, an Argentine naturalist, paleontologist, anthropologist and zoologist.