The Sunnyside Sun was founded in 1901 by William Hitchcock,[4] a member of a group of Dunkards who were migrating from South Dakota in search of a site for a Christian Cooperative Colony.
[6] In 1914, Yancey Freeman of the Sun was elected vice president of the Yakima-Benton-Kittitas Press Association, an organization newly formed to obtain uniform advertising rates in the Yakima valley.
[8] Also in 1922, the Sun joined with other Washington newspapers, including the Grandview Herald, Ellensburg Record, Wapato Independent, Toppenish Review, Toppenish Tribune, Kennewick Courier-Reporter, Zillah Mirror, Richland Advocate, and Prosser Record-Bulletin to advocate for the McNary-Smith Reclamation Bill.
The newspaper's contents were used as a basis for comparing the relative wealth and population of towns in its part of the Yakima Valley.
[16] In April 2024, owner Andy McNab sold the Sunnyside Sun to Ileana Martinez and Job Wise.