It happened at around 7 p.m. CST near Kinley, Sask., which is approximately 55 kilometres west of Saskatoon. The two were driving the truck on Highway 14 where Eagle Creek meets the road.
RCMP say conditions were icy and it appears the vehicle lost control and went off the road on the bridge.
The woman, 27, was able to make it out alive and was taken to hospital for treatment. Her condition is unknown. The man, 56, was unable to get outside of the submerged vehicle. He died at the scene.
The Saskatoon Fire Department's divers were called to fight the underwater current and connect a cable to pull the vehicle out. They say the water was deep and frigid, and a significant current made it difficult for rural fire department members to manage without help from the dive team and its equipment.
RCMP are still investigating.