Rainbow Falls is the name of several waterfalls:
New Zealand: Rainbow Falls (Waianiwaniwa), at Kerikeri Āniwaniwa Falls (Rainbow Falls) near Lake Waikaremoana Canada: Rainbow Falls, British Columbia United States: Rainbow Falls, Adirondack State Park, New York Rainbow Falls (California), Devils Postpile National Monument, California Rainbow Falls (Chattooga River), Cashiers, North Carolina Rainbow Falls (Chelan County), Stehekin, Washington Rainbow Falls (Hawaii), Hilo, Hawaii Rainbow Falls (Horsepasture River), Transylvania County, North Carolina Rainbow Falls (Manitou Springs, Colorado) Rainbow Falls (Michigan), Black River, Michigan Rainbow Falls (Missouri River), Great Falls, Montana Rainbow Falls (Montana), Glacier National Park Rainbow Falls (Rutherford County), Rutherford County, North Carolina Rainbow Falls State Park, Lewis County, Washington
Computing Systems: SPARC T3, a microprocessor also known as "Rainbow Falls"
Other: Rainbow Falls Trail Rainbow Falls (My Little Pony: Friendship Is Magic), an episode of the fourth season of My Little Pony: Friendship Is Magic