Henry Kelsey (c. 1664 – 1 November 1724) was an English fur trader, explorer, and sailor who played an important role in establishing the Hudson's Bay Company in Canada.

He is the first recorded European to have visited the present-day provinces of Saskatchewan and, possibly, Alberta, as well as the first to have explored the Great Plains from the north.

[2] In 1690, HBC governor at York Factory, George Geyer, sent Kelsey on a journey up the Nelson River "to call, encourage, and invite the remoter [First Nations people] to a trade with us."

Kelsey left York Factory on 12 June 1690 with a group of indigenous people and proceeded by canoe up the Nelson River (southwest).

Kelsey and the First Nations people reached a place he named Deering's Point, probably near present-day The Pas, Manitoba, on 10 July after a journey of 600 miles; they had passed through five lakes and undertaken 33 portages.

On 15 July 1691, he set out from Deering's Point "to discover and bring to commerce the "Naywatame poets," an Indian people of the Great Plains.

His apparent goal was to reach the First Nations people of the richer lands of the Aspen Parkland and prairies to his south and west.

[5] Entering the aspen parkland, possibly near the Touchwood Hills, he encountered the Assiniboine, a buffalo-hunting people of the Great Plains.

Continuing his journey, possibly to a point south and west of Saskatoon, Kelsey tried to make peace between the Assiniboine and their neighbours, the Naywatame poets.

Identification of them as Hidatsa or Mandan is proposed, although those tribes were resident 300 miles further south along the Missouri River in North Dakota.

Kelsey wintered with the Indians and returned to York Factory in the summer of 1692, accompanied by numerous Assiniboine and Cree eager for trade with the HBC.

In 1714 he made his sixth journey across the Atlantic Ocean, appointed as Deputy Governor of York Factory, which the British had recaptured from the French.