Rainy Peak is a summit in the Cascade Range in the U.S. state of Washington. It is located south of Rainy Pass and southeast of Frisco Mountain on the borders of the Stephen Mather Wilderness and North Cascades National Park. Its nearest higher peak is Corteo Peak, to the northwest. Precipitation runoff from Rainy Peak drains into Rainy Lake and tributaries of Bridge Creek. The retreating Lyall Glacier in its north cirque contributes to waterfalls which tumble into Rainy Lake.