St. Jacob or Saint Jacob is a village in Madison County, Illinois, United States. The population was 1,358 at the 2020 census, up from 1,098 in 2010.

St. Jacob derives its name from Jacob Schutz, who operated a store, saloon and tavern called the St. Jacob House. Earl E. Herrin (1892–1964), Illinois state representative and businessman, was born in St. Jacob. Shawn Mcsparin, drummer for country rock band Shotgun Creek, also calls Saint Jacob home.

St. Jacob is located in southeastern Madison County at 38°43′1″N 89°46′2″W / 38.71694°N 89.76722°W / 38.71694; -89.76722 (38.716897, -89.767122). U.S. Route 40 passes through the north side of the village, leading northeast 6 miles (10 km) to Highland and west the same distance to Troy. Downtown St. Louis is 26 miles (42 km) to the west.

According to the U.S. Census Bureau, St. Jacob has a total area of 0.85 square miles (2.20 km), of which 0.01 square miles (0.03 km), or 0.82%, are water. The village drains west to tributaries of Silver Creek, a south-flowing tributary of the Kaskaskia River.

Historical population

Census	Pop.	Note	%±
1880	461		—
1890	475		3.0%
1900	464		−2.3%
1910	534		15.1%
1920	485		−9.2%
1930	451		−7.0%
1940	439		−2.7%
1950	478		8.9%
1960	529		10.7%
1970	659		24.6%
1980	792		20.2%
1990	752		−5.1%
2000	801		6.5%
2010	1,098		37.1%
2020	1,358		23.7%
U.S. Decennial Census

At the 2000 census there were 801 people, 301 households, and 232 families in the village. The population density was 1,433.1 inhabitants per square mile (553.3/km). There were 321 housing units at an average density of 574.3 per square mile (221.7/km). The racial makeup of the village was 98.25% White, 0.50% Native American, 0.37% Asian, 0.50% from other races, and 0.37% from two or more races. Hispanic or Latino of any race were 1.75%.

Of the 301 households 37.2% had children under the age of 18 living with them, 67.8% were married couples living together, 6.0% had a female householder with no husband present, and 22.9% were non-families. 19.6% of households were one person and 9.0% were one person aged 65 or older. The average household size was 2.66 and the average family size was 3.01.

The age distribution was 27.8% under the age of 18, 8.0% from 18 to 24, 30.3% from 25 to 44, 22.7% from 45 to 64, and 11.1% 65 or older. The median age was 34 years. For every 100 females, there were 99.8 males. For every 100 females age 18 and over, there were 95.9 males.

The median household income was $47,917 and the median family income was $55,417. Males had a median income of $36,000 versus $25,938 for females. The per capita income for the village was $20,340. About 3.3% of families and 9.7% of the population were below the poverty line, including 18.5% of those under age 18 and none of those age 65 or over.

• St. Jacob Township, Madison County, Illinois

• Official website