Guarinisuchus is an extinct genus of marine crocodyliform from the Early Paleocene 62 million years ago of the Maria Farinha Formation, Brazil. The type species is G. munizi. It was a dominant predator in its environment, and probably reached a length of 3 m. Guarinisuchus appears to be closely related to marine crocodylomorphs found in Africa, which supports the hypothesis that the group originated in Africa and migrated to South America before spreading into the waters off the North American coast.