Mount Duff, also named Boundary Peak 174, is a mountain in Alaska and British Columbia, located on the Canada–United States border, and part of the Southern Icefield Ranges of the Saint Elias Mountains. It was named in 1923 for Sir Lyman Poore Duff, (1865-1955), a junior counsel before the International Boundary Commission in 1903, and Judge of the Supreme Court of Canada.

• List of Boundary Peaks of the Alaska-British Columbia/Yukon border

• "Mount Duff". BC Geographical Names.