Fort Nelson may refer to

Fort Nelson, British Columbia, Canada, a town
Fort Nelson River, British Columbia
Fort Nelson, Hampshire, a Palmerston Fort (now a museum) in England
Fort Nelson, a fur trading post at the mouth of the Nelson River, Manitoba, Canada, the first headquarters of the Hudson's Bay Company
Fort Nelson (Kentucky), United States, built in 1781
Fort Nelson (Virginia), United States, first constructed in 1776