John Marshall Dowe (September 1, 1896 – May 15, 1946) was an American politician who served as Connecticut State Comptroller (1941–1943, 1945–1946).

When he died in office in 1946, the Connecticut General Assembly appointed Raymond S. Thatcher to fill the vacancy.

In 1917, he left Brown without a degree to enlist in the United States Army and saw active duty overseas in World War I with the 103rd Field Artillery Regiment, 26th Infantry Division, American Expeditionary Force.

[2] Returning to Killingly in May 1919, Dowe took over the running of the family stationery business, which his grandfather had established in 1860.

[2] At the age of 49, Dowe suffered a heart attack and died at Saint Francis Hospital in Hartford on May 15, 1946.