A member municipality of the Central Kootenay Regional District, the name derives from the adjacent Kaslo River.

"[4] Before European arrival, the area was home to the semi-nomadic Kutenai (Ktunaxa) and Lakes (Sinixt) tribes.

Settlers came and used it as a sawmill site in 1889, but soon after Kaslo expanded as a result of the silver boom of the late 19th century.

Kaslo's fortunes faded after the end of the silver rush, and the widespread collapse of mining activity following World War I, but the growth in fruit farming and logging partially offset this decline.

[5] Kaslo has been featured on the historical television series Gold Trails and Ghost Towns (season 2, episode 2).