| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 28,392 | 50,460 | 81,391 | |
| 2020 | R | 30,679 | 50,772 | 83,821 | |
| 2016 | R | 22,171 | 40,920 | 70,486 | |
| 2012 | R | 26,403 | 40,500 | 68,807 | |
| 2008 | R | 32,038 | 36,483 | 70,416 | |
| 2004 | R | 24,120 | 40,903 | 66,286 | |
| 2000 | R | 20,370 | 33,922 | 57,499 | |
| 1996 | R | 22,992 | 26,367 | 55,882 | |
| 1992 | R | 20,163 | 22,822 | 56,450 | |
| 1988 | R | 21,987 | 28,069 | 50,647 | |
| 1984 | R | 19,437 | 34,124 | 54,153 | |
| 1980 | R | 15,272 | 27,332 | 48,313 | |
| 1976 | R | 18,329 | 25,201 | 44,125 | |
| 1972 | R | 13,602 | 25,205 | 40,237 | |
| 1968 | R | 11,682 | 19,898 | 33,857 | |
| 1964 | D | 17,446 | 15,571 | 33,239 | |
| 1960 | R | 12,356 | 19,467 | 32,006 | |
| 1956 | R | 10,088 | 18,664 | 28,752 | |
| 1952 | R | 8,750 | 17,556 | 26,357 | |
| 1948 | R | 9,718 | 10,342 | 20,384 | |
| 1944 | R | 8,140 | 8,706 | 16,925 | |
| 1940 | D | 9,036 | 8,479 | 17,655 | |
| 1936 | D | 8,575 | 5,193 | 14,016 | |
| 1932 | D | 5,777 | 5,386 | 11,483 | |
| 1928 | R | 3,205 | 6,904 | 10,141 | |
| 1924 | R | 1,172 | 4,715 | 8,433 | |
| 1920 | R | 2,782 | 5,714 | 8,780 | |
| 1916 | D | 4,259 | 3,281 | 7,801 | |
| 1912 | D | 1,193 | 1,004 | 3,828 | |
| 1908 | R | 1,114 | 1,803 | 3,185 | |
| 1904 | R | 436 | 1,249 | 1,774 | |
| 1900 | R | 654 | 816 | 1,497 | |
| 1896 | D | 575 | 429 | 1,009 | |
| 1892 | R | 369 | 479 | 889 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Home to Billings, Montana's largest city, Yellowstone County combines an urban commercial hub with surrounding ranching plains — a mix that still produces some of the most lopsided Republican margins of any high-population county in the state.
The Republican margin in Yellowstone County reached its widest at forty-six points in 1904. The margin in 2024 was twenty-seven points, in line with the county's deep historical pattern.
Yellowstone County's loyalty is rooted in its place. Median household income of $76,570, a 86% non-Hispanic-white share, and a population of 168,957 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of Pondera County and Teton County.