[4] Cheatham County is located in Middle Tennessee, and is part of the Nashville-Davidson–Murfreesboro–Franklin, TN Metropolitan Statistical Area.

[5] The county is bisected from northwest to southeast by the Cumberland River, with Ashland City on its northern bank.

The southern portion of the county is bisected from southeast to northwest by the Harpeth River, which meanders through generally hilly country, and along whose course are located the communities of Kingston Springs, largely to the north of I-40, and Pegram, along U.S. Route 70 (US 70).

The western border of the central portion of the county is defined by the course of the Harpeth.

North of Ashland City the hills subside into more level highlands, where the community of Pleasant View is located just south of I-24, which generally delineates the county's northern border.

As of the 2020 United States census, there were 41,072 people, 15,089 households, and 11,022 families residing in the county.

The last Democrat to carry this county on a presidential level was Bill Clinton in 1996.