Waldo is a town located in the U.S. state of Arkansas. It is within Columbia County approximately 7 miles in northwest Magnolia. It has a total area of 2.33 square miles at 33°21′7″N 93°17′40″W. The elevation is 361 feet above sea level. As of the 2010 census data, it had a total population of 1,372. The population density was 549.46/sq mi. Estimated per capita income in 2016 was $23,703. It has Zip code 71770.