James Alphonsus Hamill (March 30, 1877 – December 15, 1941) was an American attorney and Democratic Party politician.

At the Paris Peace conference of 1919 he served as counsel to the unrecognized Ukrainian delegation.

He attended Saint Peter's College receiving his Bachelor's degree in 1897, and graduated from New York Law School in 1899; He was admitted to the bar of the State of New Jersey in 1900.

[2] During Eamon de Valera's visit to the United States in 1919, Hamill introduced a resolution in the House of Representatives calling on President Wilson to refuse to receive Auckland Geddes as Ambassador of both Britain and Ireland, but to receive Dr, Patrick McCartan, who had been sent by the Provisional government of Ireland as the Irish ambassador.

[3] Hamill represented Mayor Frank Hague in the free speech case which was instituted in July 1938 by the C.I.O.