Witt is a city in Montgomery County, Illinois, United States.

Witt is in eastern Montgomery County along Illinois Route 16, which leads 11 miles (18 km) southwest to Hillsboro, the county seat, and 4.5 miles (7.2 km) northeast to Nokomis.

According to the U.S. Census Bureau, Witt has a total area of 1.2 square miles (3.1 km2), all land.

The racial makeup of the city was 99.50% White, 0.10% African American, 0.20% Asian, and 0.20% from two or more races.

35.4% of all households were made up of individuals, and 19.2% had someone living alone who was 65 years of age or older.