| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 5,667 | 13,302 | 19,260 | |
| 2020 | R | 5,981 | 13,038 | 19,381 | |
| 2016 | R | 5,368 | 11,688 | 18,603 | |
| 2012 | R | 7,732 | 10,176 | 18,461 | |
| 2008 | R | 8,399 | 10,407 | 19,232 | |
| 2004 | R | 6,975 | 11,397 | 18,516 | |
| 2000 | R | 6,175 | 9,540 | 16,242 | |
| 1996 | R | 6,343 | 7,469 | 15,893 | |
| 1992 | R | 5,735 | 7,195 | 17,211 | |
| 1988 | R | 5,448 | 9,566 | 15,153 | |
| 1984 | R | 5,004 | 10,951 | 16,130 | |
| 1980 | R | 5,096 | 9,358 | 15,639 | |
| 1976 | R | 5,850 | 7,526 | 13,679 | |
| 1972 | R | 4,377 | 8,914 | 13,630 | |
| 1968 | R | 5,686 | 7,348 | 13,959 | |
| 1964 | D | 8,707 | 5,048 | 13,755 | |
| 1960 | R | 5,207 | 8,912 | 14,119 | |
| 1956 | R | 3,941 | 8,786 | 12,727 | |
| 1952 | R | 4,161 | 8,834 | 12,995 | |
| 1948 | R | 4,454 | 5,927 | 10,409 | |
| 1944 | R | 3,634 | 7,450 | 11,084 | |
| 1940 | R | 4,313 | 8,010 | 12,323 | |
| 1936 | D | 5,608 | 5,000 | 11,670 | |
| 1932 | D | 6,532 | 3,871 | 10,595 | |
| 1928 | R | 3,487 | 6,289 | 9,776 | |
| 1924 | R | 3,227 | 4,841 | 9,213 | |
| 1920 | R | 3,723 | 5,987 | 9,890 | |
| 1916 | D | 3,359 | 2,565 | 6,055 | |
| 1912 | D | 2,784 | 872 | 5,504 | |
| 1908 | D | 3,754 | 2,531 | 6,482 | |
| 1904 | D | 3,216 | 3,032 | 6,392 | |
| 1900 | D | 3,766 | 2,684 | 6,578 | |
| 1896 | D | 4,239 | 2,414 | 6,703 | |
| 1892 | D | 3,311 | 2,062 | 5,876 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Defiance County, anchored by its small manufacturing city on the Maumee River, has shifted steadily rightward over two decades — its 2024 presidential margin of R+39.9 reflects a broader rural northwest Ohio realignment away from its once-competitive past.
The Republican margin in Defiance County reached its widest at forty points in 2024. The margin in 2024 was forty points, in line with the county's deep historical pattern.
Defiance County's loyalty is rooted in its place. Median household income of $73,064, a 87% non-Hispanic-white share, and a population of 38,343 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 Wyandot County and Orange County.