Robert Julian Onderdonk (1882
–1922) was an American Impressionist painter born and active in San Antonio, Texas. He received early artistic instruction from his father, painter Robert Jenkins Onderdonk. Onderdonk established himself within the Impressionist movement, focusing his practice on the landscapes of his native Texas.
His oeuvre primarily consists of landscape paintings depicting the Texas region, with a particular emphasis on the Bluebonnet, the state's floral emblem. Onderdonk's Impressionist approach rendered the distinct light and atmosphere of the Texan environment.
Onderdonk is frequently referred to as "the father of Texas painting," a designation reflecting his significant contribution to the regional art tradition.
