William Eleroy Curtis (November 5, 1850 – October 5, 1911) was an American journalist, author, diplomat, political activist, and exhibitor. He was a prominent proponent of Pan-Americanism. Curtis' partisan reporting earned him patronage appointments and advanced his ideological goals. His career reflected the influence of bias, cronyism, and imperialism on journalism during the Gilded Age. Curtis held a series of leadership roles in the State Department, as well as the supranational organizations which anticipated the Organization of American States.
