| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 8,080 | 22,758 | 31,049 | |
| 2020 | R | 9,138 | 23,560 | 33,088 | |
| 2016 | R | 8,785 | 21,108 | 31,848 | |
| 2012 | R | 14,156 | 16,758 | 32,181 | |
| 2008 | D | 16,302 | 15,422 | 32,536 | |
| 2004 | D | 17,576 | 15,589 | 33,322 | |
| 2000 | D | 15,980 | 12,625 | 30,141 | |
| 1996 | D | 17,705 | 8,213 | 30,639 | |
| 1992 | D | 18,527 | 8,614 | 33,421 | |
| 1988 | D | 19,515 | 12,214 | 31,973 | |
| 1984 | D | 19,458 | 15,170 | 34,856 | |
| 1980 | D | 16,653 | 13,601 | 32,024 | |
| 1976 | D | 21,162 | 13,550 | 35,219 | |
| 1972 | R | 14,800 | 17,628 | 32,878 | |
| 1968 | D | 22,056 | 11,512 | 36,046 | |
| 1964 | D | 28,180 | 9,693 | 37,873 | |
| 1960 | D | 23,805 | 18,146 | 41,951 | |
| 1956 | R | 18,991 | 19,230 | 38,221 | |
| 1952 | D | 24,759 | 17,693 | 42,452 | |
| 1948 | D | 23,217 | 13,283 | 37,143 | |
| 1944 | D | 24,093 | 15,485 | 39,578 | |
| 1940 | D | 28,618 | 17,705 | 46,323 | |
| 1936 | D | 30,545 | 14,511 | 45,481 | |
| 1932 | D | 20,291 | 15,029 | 36,885 | |
| 1928 | R | 12,807 | 20,969 | 34,468 | |
| 1924 | R | 8,074 | 16,378 | 30,035 | |
| 1920 | R | 13,347 | 14,761 | 29,201 | |
| 1916 | D | 7,911 | 7,526 | 17,046 | |
| 1912 | D | 5,412 | 5,267 | 15,491 | |
| 1908 | R | 7,750 | 8,193 | 17,063 | |
| 1904 | R | 4,801 | 8,170 | 14,396 | |
| 1900 | R | 6,251 | 8,217 | 14,852 | |
| 1896 | R | 6,413 | 7,699 | 14,348 | |
| 1892 | R | 6,123 | 6,329 | 13,109 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Belmont County, anchored by the Ohio Valley's legacy coal and gas economy, recorded an R+47.3 presidential margin in 2024 — a striking shift from a county that voted measurably more competitively just a decade ago.
The unraveling was not abrupt. The Democratic margin in Belmont County peaked at forty-nine points in 1964; it narrowed steadily over the late twentieth century. The 2012 election delivered the county to the Republican party for the first time in many years, by a margin of eight points. By 2024, the margin had widened further.
The economic and demographic context is severe. Belmont County's median household income of $57,017 is among the lowest of any county in the United States; 16% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Jefferson County and Brooke County.