Dease Lake /ˈdiːs/ is a small community in the Cassiar Country of the Northern Interior of British Columbia, Canada.

Dease Lake is the last major centre before the Alaska Highway while driving northbound, and also the junction to Telegraph Creek and the Grand Canyon of the Stikine.

The town sits astride a drainage divide separating the basins of the Dease River (to the north) from that of the Tanzilla (to the south), a tributary of the Stikine.

The Lake had been named in 1834 for Chief Factor Peter Warren Dease, and would become a major junction for miners travelling to the gold rush in Cassiar (later an asbestos mine).

Summers are mild, coupled with chilly nights while winters are severely cold and snowy, with annual snowfall averaging 212.8 cm (83.78 in).