[2] The county is named for Founding Father and U.S. President James Madison.

[3] Madison County is part of the Jackson, MS Metropolitan Statistical Area.

[4] The southeastern border of the county is defined by the old course of the Pearl River before it was dammed to create the 33,000 acres (130 km2) Ross Barnett Reservoir.

[6] Madison County was the site of the Mississippi Slave Insurrection Scare of 1835 at Beatties Bluff.

[7] As of the 2020 United States Census, there were 109,145 people, 40,046 households, and 28,374 families residing in the county.

Madison County has the highest per capita income in the State of Mississippi.

It is the only county in Mississippi with a per capita income higher than the national average.