Waldo is a city in Columbia County, Arkansas, United States.

The small community was once a booming rail city on the Cotton Belt train route.

Consistently these teams made playoffs and on numerous occasions won the state championship.

[4] The Waldo Water Tower, completed in 1936 by the Pittsburgh-Des Moines Steel Co., is listed on the National Register of Historic Places.

According to the United States Census Bureau, the city has a total area of 2.3 square miles (5.9 km2), all land.

[3] Waldo, located in South Arkansas near the northern Louisiana border, has a subtropical climate like that of the Bayou State and similar terrain.

As of the 2020 United States census, there were 1,151 people, 558 households, and 329 families residing in the city.