Caledonia is a village in Marion County, Ohio, United States. The population was 560 at the 2020 census.

The village was named after Caledonia, an ancient name for Scotland, the ancestral home of a large share of the first settlers.

The northern side of Caledonia is the location of the Caledonia Bowstring Bridge, which is listed on the National Register of Historic Places.

According to the United States Census Bureau, the village has a total area of 0.23 square miles (0.60 km), all land.

Caledonia is located along the Whetstone River in the Sandusky Plains: a historically important tended prairie region, & one of only a handful of post-glaciation prairie regions in Ohio.

Historical population

Census	Pop.	Note	%±
1870	419		—
1880	627		49.6%
1890	757		20.7%
1900	682		−9.9%
1910	562		−17.6%
1920	492		−12.5%
1930	526		6.9%
1940	629		19.6%
1950	655		4.1%
1960	673		2.7%
1970	792		17.7%
1980	759		−4.2%
1990	644		−15.2%
2000	578		−10.2%
2010	577		−0.2%
2020	560		−2.9%
2023 (est.)	550		−1.8%
U.S. Decennial Census

As of the census of 2020, there were 560 people, 246 housing units, 230 households, and 154 families living in the village. The population density was 2,434.8 inhabitants per square mile (940.1/km). There were 246 housing units at an average density of 1,069.6 units per square mile (413.0 units/km). The racial makeup of the village was 93.6% White, 0.3% African American, 0.0% Asian, 0.5% from other races, 5.0% from two or more races, and 0.5% American Indian/Alaskan Native. Hispanic or Latino of any race were 1.25% of the population.

There were 230 households, with the average household size being 3.34. 58.0% were married couples living together.

The median age in the village was 32.2 years. 25.9% of residents were under the age of 18; 7.4% were between the ages of 18 and 24; 32.2% were from 25 to 44; 19.9% were from 45 to 64; and 14.8% were 65 years of age or older. The gender makeup of the village was 50.5% male and 49.5% female.

The median income for a household in the village was $64,286, and the median income for a family was $75,625. About 11.7% of the population were living below the poverty line.

As of the census of 2010, there were 577 people, 232 households, and 174 families living in the village. The population density was 2,508.7 inhabitants per square mile (968.6/km). There were 260 housing units at an average density of 1,130.4 units per square mile (436.4 units/km). The racial makeup of the village was 97.4% White, 1.6% African American, 0.2% Asian, 0.7% from other races, and 0.2% from two or more races. Hispanic or Latino of any race were 0.5% of the population.

There were 232 households, of which 31.5% had children under the age of 18 living with them, 57.3% were married couples living together, 12.1% had a female householder with no husband present, 5.6% had a male householder with no wife present, and 25.0% were non-families. 21.1% of all households were made up of individuals, and 10.3% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 2.86.

The median age in the village was 40.2 years. 24.1% of residents were under the age of 18; 6.6% were between the ages of 18 and 24; 26% were from 25 to 44; 27.2% were from 45 to 64; and 16.3% were 65 years of age or older. The gender makeup of the village was 47.5% male and 52.5% female.

As of the census of 2000, there were 578 people, 230 households, and 169 families living in the village. The population density was 2,568.0 inhabitants per square mile (991.5/km). There were 242 housing units at an average density of 1,075.2 units per square mile (415.1 units/km). The racial makeup of the village was 99.31% White, 0.35% African American, and 0.35% from two or more races. Hispanic or Latino of any race were 0.35% of the population.

There were 230 households, out of which 32.6% had children under the age of 18 living with them, 60.0% were married couples living together, 8.7% had a female householder with no husband present, and 26.5% were non-families. 23.9% of all households were made up of individuals, and 12.2% had someone living alone who was 65 years of age or older. The average household size was 2.51 and the average family size was 2.92.

In the village, the population was spread out, with 25.3% under the age of 18, 7.1% from 18 to 24, 30.3% from 25 to 44, 25.4% from 45 to 64, and 11.9% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 95.9 males. For every 100 females age 18 and over, there were 97.3 males.

The median income for a household in the village was $40,804, and the median income for a family was $46,563. Males had a median income of $34,375 versus $22,344 for females. The per capita income for the village was $17,423. About 1.9% of families and 4.9% of the population were below the poverty line, including none of those under age 18 and 5.3% of those age 65 or over.

River Valley Local School District operates two elementary schools, one middle school, and River Valley High School.

From the 1920s until 2021, Caledonia had a public library: a branch of Marion Public Library. This branch closed in the middle of the COVID-19 pandemic, & does not have plans to reopen. The library space is currently vacant.

• Sherwood Anderson spent several years of his childhood in Caledonia, where his father worked as a harness-maker. Anderson based elements of his 1926 semi-autobiographical novel Tar: A Midwest Childhood on his time in Caledonia.
• Daniel Richard Crissinger was educated in Caledonia and served as chairman of the Federal Reserve Board between 1923 and 1927.
• Warren G. Harding was a resident of Caledonia during his childhood, and worked for a brief period of time at the community newspaper, The Argus.