Waldo is a city in Waldo Township, Russell County, Kansas, United States. As of the 2020 census, the population of the city was 30. The …Waldo is a city in Waldo Township, Russell County, Kansas, United States. As of the 2020 census, the population of the city was 30. The Union Town Company established the town of Waldo on October 1, 1888, having acquired 280 acres of land on a line of the Union Pacific Railroad. The community grew over the following decades, reaching a population of approximately 300 by 1915. A small business community, including a bank, stores, and three grain elevators, developed during the 1900s. The town served as an agricultural shipping and receiving point for the surrounding area. Waldo incorporated as a city in May 1911.