Robert Julian Onderdonk (1882 – 1922) was a Texan Impressionist painter, often called "the father of Texas painting."
When Onderdonk was young boy, he began his first art lessons under his father’s instruction. At 19, with the help of a generous neighbor, Onderdonk left Texas in order to study with the renowned American Impressionist William Merritt Chase in Southampton, New York. He studied with Chase for a couple of years and then moved to New York City to attempt to make a living as an en plein air artist. Onderdonk returned to his native San Antonio in 1909, where he produced his best work. His most popular subjects were bluebonnet landscapes.
President George W. Bush decorated the Oval Office with three of Onderdonk's paintings. The Dallas Museum of Art has several rooms dedicated exclusively to Onderdonk's work.