| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 15,969 | 42,677 | 59,438 | |
| 2020 | R | 15,663 | 41,371 | 57,972 | |
| 2016 | R | 13,120 | 37,079 | 53,567 | |
| 2012 | R | 16,383 | 34,606 | 52,221 | |
| 2008 | R | 18,372 | 33,417 | 52,915 | |
| 2004 | R | 17,606 | 33,992 | 51,760 | |
| 2000 | R | 15,584 | 26,037 | 42,841 | |
| 1996 | R | 15,540 | 19,509 | 40,005 | |
| 1992 | R | 12,547 | 19,741 | 43,006 | |
| 1988 | R | 11,138 | 24,915 | 36,434 | |
| 1984 | R | 9,695 | 26,300 | 36,315 | |
| 1980 | R | 12,893 | 19,928 | 35,808 | |
| 1976 | R | 13,074 | 18,686 | 32,413 | |
| 1972 | R | 9,121 | 21,226 | 31,012 | |
| 1968 | R | 13,228 | 16,997 | 33,577 | |
| 1964 | D | 19,379 | 12,985 | 32,364 | |
| 1960 | R | 11,770 | 22,151 | 33,921 | |
| 1956 | R | 9,229 | 20,135 | 29,364 | |
| 1952 | R | 10,462 | 19,525 | 29,987 | |
| 1948 | R | 10,066 | 13,100 | 23,255 | |
| 1944 | R | 10,476 | 14,751 | 25,227 | |
| 1940 | R | 11,799 | 14,725 | 26,524 | |
| 1936 | D | 12,754 | 11,343 | 25,286 | |
| 1932 | R | 10,677 | 12,157 | 23,402 | |
| 1928 | R | 5,867 | 16,063 | 22,066 | |
| 1924 | R | 5,296 | 11,851 | 18,901 | |
| 1920 | R | 8,076 | 13,122 | 21,770 | |
| 1916 | R | 5,582 | 5,772 | 11,873 | |
| 1912 | D | 4,310 | 3,615 | 11,125 | |
| 1908 | R | 5,369 | 6,558 | 12,215 | |
| 1904 | R | 3,646 | 6,793 | 10,879 | |
| 1900 | R | 5,127 | 6,197 | 11,505 | |
| 1896 | R | 5,387 | 6,051 | 11,503 | |
| 1892 | R | 4,271 | 5,110 | 9,969 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Miami County, anchored by Troy and Piqua in the Great Miami River corridor, has delivered Republican presidential nominees by landslide margins for decades, reflecting a predominantly white, small-city electorate with deep roots in manufacturing and agriculture.
The Republican margin in Miami County reached its widest at forty-six points in 1928. The margin in 2024 was forty-five points, in line with the county's deep historical pattern.
Miami County's loyalty is rooted in its place. Median household income of $76,817, a 90% non-Hispanic-white share, and a population of 110,296 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 Auglaize County and Anderson County.