Chalahn Falls is a waterfall on Toolona Creek within Lamington National Park in Queensland, Australia. It sits along the popular Toolona Creek Circuit, a 17.

4-kilometre grade-4 loop track accessible from O'Reilly's, with Queensland Parks advising approximately six hours of walking time.

The falls are reached roughly two to two-and-a-half hours into the hike, after passing several other cascades including Triple Falls, Dwandarra Falls, and Gwongurai Falls.

The waterfall is considered a highlight of the circuit and is particularly impressive after solid rainfall, when strong flows make it highly photogenic. During drier periods the volume diminishes, though the surrounding rainforest scenery remains rewarding.

Wildlife can be spotted nearby — the vivid blue Lamington Crayfish, native to the area, has been observed along the creek banks close to the falls.