| Named By: | Chris Brochu in 1997 |
| Time Period: | Late Cretaceous-Eocene |
| Location: | Canada, including Alberta - Scollard Formation, and Saskatchewan - Ravenscrag Formation, and the USA, including the states of Colorado - DeBeque Formation, Laramie Formation and Ohio Creek Formation, Montana - Hell Creek Formation and Tullock Formation, New Jersey - Hornerstown Formation, North Carolina - Tar Heel Formation, North Dakota - Bullion Creek Formation and Hell Creek Formation, Texas, Wyoming - Bridger Formation, Green River Formation, Lance Formation, Willwood Formation |
| Size: | Up to 2.8 meters long, though there is some variance between species |
| Diet: | Carnivore/Piscivore |
| Fossil(s): | Skulls and post cranial remains |
| Classification: | | Chordata | Reptilia | Crocodylomorpha | Crocodylia | |
| Also known as: | | Leidysuchus acutidentatus | Leidysuchus formidabilis | Leidysuchus sternbergii | Leidysuchus wilsoni | |
Borealosuchus (meaning "boreal crocodile") is an extinct genus of crocodylians that lived from the Late Cretaceous to the Eocene in North America. It was named by Chris Brochu in 1997 for several species that had been assigned to Leidyosuchus. The species assigned to it are: B. sternbergii, the type species, from the Maastrichtian (Late Cretaceous) of Colorado, Montana, North Dakota, South Dakota, and Wyoming; B. acutidentatus, from the Paleocene of Saskatchewan; B. formidabilis, from the Paleocene of North Dakota; B. griffithi, from the Paleocene of Alberta; and B. wilsoni, from the Eocene of Wyoming. B. formidabilis is particularly well-known, represented by the remains of many individuals from the Wannagan Creek site in North Dakota.
Borealosuchus was a mid-sized crocodylian; B. acutidentatus reached up to 2.8 metres (9.2 ft) in length with a 36 centimetres (14 in) skull.