Dorr Eugene Felt (March 18, 1862 – August 7, 1930) was an American inventor and industrialist who was known for having invented the Comptometer,[1] an early computing device, and the Comptograph, the first printing adding machine.

Dorr E. Felt was born in Beloit, Wisconsin[3] where he grew up on the family farm and which he left at age 14 to seek employment.

At 16, "his bent of mind, leaning towards mechanics, led him to seek work in a machine shop in Beloit where he found his first employment in the spring of 1878.

The original macaroni box prototype and the first Comptograph ever sold are now part of the Smithsonian Museum collection of antique calculators.

Dorr Felt also was the first ambassador for the Department of Commerce formed to study labor abroad after World War I.

He made his home in Chicago and summered in Laketown Township, Michigan, where the Dorr E. Felt Mansion[9] is registered on the list of National Historic Places.