"Etomami" is a First Nations word that means "a place that three rivers join".

The river's source is at the north end of the bifurcating Etomami Lake in the RM of Preeceville No.

334 and flows northward through a deep-cut valley into the RM of Hudson Bay No.

In 1691, Hudson's Bay Company fur trader and explorer Henry Kelsey traversed the length of the Etomami River while in search of a route to the aspen parkland region.

Following a trail known to be used by the local Indigenous peoples, at Etomami Lake, he crossed over to the Lilian River system.