Geoffrey O'Hara (February 2, 1882 – January 31, 1967) was a Canadian-American composer, singer and music professor.

O'Hara entered the Royal Military College of Canada in Kingston, Ontario at age 18 and he trained with the 1st Hussars.

He was recorded on phonograph cylinder lecturing about the complexity of the music as well as singing and playing several types of Navajo traditional songs in 1914.

He also was a board member of the American Society of Composers, Authors, and Publishers (ASCAP), was the president of the Composers-Authors Guild, and served in the United Service Organizations (USO).

[2] In 1919, he married Constance Dougherty from Massachusetts, and together they had two children; the same year, he became a naturalized citizen of the United States.