Lindley Hoag Hadley (born June 19, 1861) was a Republican member of the United States House of Representatives from the state of Washington. He represented Washington’s 2nd Congressional District and served as a federal legislator during the early twentieth century. His congressional career placed him among the historical members of Congress from Washington.

Hadley served as a Representative from December 6, 1915, to March 3, 1933, completing nine terms in the U.S. House of Representatives. Throughout this period, he held office as a Republican and was identified with Washington’s 2nd District. After leaving Congress in 1933, he was a former officeholder and did not return to the House.