It was named after Major Andrew Holmes, who was killed in action at the Battle of Mackinac Island.

In 1863, during the Civil War, numerous small anti-draft riots took place, mainly in the German-speaking areas.

Holmes County at the time was a Democratic stronghold, dominated by its Pennsylvania Dutch settlers, along with many recent German immigrants.

With the passage of the Conscription Act in March 1863, Holmes County politicians denounced both Congress and President Lincoln as despotic, saying that forced military service was little different from slavery.

Violent protests broke out in June, and they continued until the Union Army marched into the county and declared martial law.

[10] Stephen E. Towne in 2019 using archival records argues that many of the resisters belonged to secret organizations that opposed Union tactics to defeat the Confederacy.

As of the 2010 United States Census, there were 42,366 people, 12,554 households, and 10,035 families living in the county.

Holmes County has a relatively high number of residents who do not speak English at home.

[22] 42.92% of the total population and 50.28% of the children in 5-17 age range uses German/Pennsylvania German or "Dutch"[22] at home.

Religion in Holmes County, according to ARDA (2020) [26][failed verification] Tourism is an important part of the economy.

[37] Tourism is centered on the Amish community, which makes up almost half the county's population, the highest density in the world.

The county has since become a Republican stronghold, with Lyndon B. Johnson being the only Democrat since 1940 to carry it, in his 1964 landslide, although Harry S. Truman came within just 16 votes of winning it in 1948.

The high Amish population means that a large proportion of residents in Holmes County do not vote, even compared to turnout standards in much of the United States.

CDP = Census-designated place UIC = Unincorporated community Holmes County Airport (FAA LID: 10G) located two miles southwest of Millersburg.

Holmes County is home of more Amish affiliations than any other place in the world.