Lower Cliffside Rapids is a Class III rapid located at mile 88. 5 on the Middle Fork Salmon River, where the river bends sharply left around a cliff with large rocks suddenly appearing in the channel.

The rapid is more challenging at high flows when staying inside the curve is critical, and it has proven difficult for kayakers with frequent swims reported.

This rapid is part of the renowned Impassible Canyon section and is typically encountered on multi-day wilderness river trips in the lower portion of the Middle Fork.