Tomás Herrán y Mosquera (September 21, 1843–1904) was a Colombian diplomat, a signatory to and namesake of the Hay–Herran Treaty.
At the time of the Hay–Herran Treaty, Herrán was Colombian chargé d'affaires to the United States. Herrán's papers were later published as The Letters of Tomás Herrán and the Panama Crisis, 1900-1903, edited by Thomas J. Dodd, Jr..