Daniel Webster Marsh (August 15, 1838 – June 27, 1916) was a businessman and 4th mayor of Calgary, Alberta, Canada.

He was born in the United States, at Hudson, New Hampshire to Enoch Sawyer March and Margaret Whittier.

Marsh spent his youth in Nashua, New Hampshire, attending the public schools, and starting his working career there.

As a young man, he served with the 30th Wisconsin Infantry Regiment and was a part of the Dakota Territory Indian campaigns.

He arranged for his nephew, Horace A. Greeley, to manage the store in Maple Creek.