Fourth Falls, also called Upper Falls or Gooch's Falls, is the highest of the Royal River's four waterfalls in Yarmouth, Maine and one of the river's key industrial sites. The river's total 45-foot drop near navigable water attracted early settlement, and from 1674 into the mid-20th century the four falls powered 57 mills. At Fourth Falls, industries included an iron refinery by 1753, a long-successful double sawmill built by local families, a tannery, three shoe manufacturers, and a poultry-processing plant. Nearby, Charles H. Weston operated a machine shop and foundry from 1876 to 1892, and in 2025 the town approved dam removal to improve the river's ecology.