| Ernest S. Brown | |
| Jr/Sr1: | United States Senator |
| State1: | Nevada |
| Appointed1: | Charles H. Russell |
| Term Start1: | October 1, 1954 |
| Term End1: | December 1, 1954 |
| Preceded1: | Pat McCarran |
| Succeeded1: | Alan Bible |
| Office2: | District Attorney of Washoe County, Nevada |
| Term Start2: | January 1935 |
| Term End2: | February 1942 |
| Predecessor2: | Melvin E. Jepson |
| Successor2: | Douglas Busey |
| Office3: | Member of the Nevada State Assembly |
| Term Start3: | 1933 |
| Term End3: | 1935 |
| Alongside3: | Harry Dunseath, Fred D. Black, W. Holmes Goodwin, J. H. Cahill, C. P. Johnson |
| Constituency3: | Reno district |
| Predecessor3: | Fred D. Black, Harry Dunseath, August Frohlich, Guy Walts, Fred Small, E. J. Kleppe |
| Successor3: | Curry Jameson, Fred Phillips, W. Holmes Goodwin, O. M. Renfro, Jack Horgan, James Clark |
| Birth Date: | 25 September 1903 |
| Birth Place: | Alturas, California, U.S. |
| Death Place: | Reno, Nevada, U.S. |
| Party: | Republican |
| Education: | University of Nevada at Reno |
| Profession: | Attorney |
Ernest S. Brown (September 25, 1903July 23, 1965) served briefly as a United States senator from Nevada in 1954.
Ernest Spargur Brown, born in Alturas, California, moved with his family to Reno, Nevada, in 1906, where he later attended the public schools. He graduated from the University of Nevada at Reno in 1927 with the Bachelor of Arts degree he had completed in 1926. Brown studied law at night while still in college, gained admission to the bar in 1927, then commenced a legal practice in Reno. He served in the Nevada State Assembly in 1933. From 1935 to February 1942, Brown was the district attorney of Washoe County. A longtime member of the military reserves, he resigned from office in 1942 to enter active service in the United States Army as a major. He advanced through the ranks to colonel during the war, and he was discharged in 1945. Brown returned to his Reno home to resume the practice of law.
On October 1, 1954, Nevada Governor Charles H. Russell, a college classmate of Brown's, appointed Brown to the U.S. Senate as a Republican to fill the vacancy caused by the death of veteran Senator Pat McCarran. Democrat Alan Bible defeated him in a special election to keep his Senate seat in November 1954. Bible assumed the seat on December 1, 1954, and Brown once again resumed the practice of law.
Brown died in Reno in 1965, and was interred in the Masonic section of Mountain View Cemetery.