It was originally known as "Pine Top", but was renamed "Stapleton" after the Staples family set up the town's first post office in the mid-19th century.

White Oak Creek, which drains Sunbright, is part of the upper watershed of the Big South Fork of the Cumberland River.

Sunbright is centered along U.S. Route 27, which connects the city to Wartburg and Harriman to the south and Huntsville, Tennessee and Lexington, Kentucky to the north.

US 27 intersects State Route 329 in the center of town, which connects Sunbright to Deer Lodge.

According to the United States Census Bureau, the city has a total area of 3.8 square miles (9.8 km2), all of it land.

As of the 2020 United States census, there were 519 people, 203 households, and 124 families residing in the city.