Simon S. McDonald (December 11, 1869 – May 24, 1956) was a North Dakota Republican Party politician who served as a North Dakota Public Service Commissioner from 1941 to 1948.

Prior to 1941, his title was North Dakota Railroad Commissioner.

He was raised on a farm, educated in the machinist trade, and was employed by daily newspapers in different parts of the United States in his early adult years.

He served as the machinist in charge of the mechanical department at the Grand Forks Herald after coming to North Dakota in March 1914.

He was appointed by Governor of North Dakota Lynn Frazier as a member of the Workmen's Compensation Bureau on April 1, 1919, and was re-appointed to the position by Governor Arthur Sorlie in 1925, and served until 1930.