Jon Hassler (March 30, 1933 – March 20, 2008) was an American writer and teacher known for his novels about small-town life in Minnesota. He held the positions of Regents Professor Emeritus and Writer-in-Residence at St. John's University in Collegeville, Minnesota.
Jon Hassler was born in Minneapolis, but spent his formative years in the small Minnesota towns of Staples and Plainview, where he graduated from high school. He received his Bachelor of Arts degree in English from St. John's University in 1955. While teaching English at three different Minnesota high schools, he received his Master of Arts degree in English from the University of North Dakota in 1960. He continued to teach at the high school level until 1965, when he began his collegiate teaching career: first at Bemidji State University, then Brainerd Community College (now called Central Lakes College), and finally at Saint John's, where he became the Writer-in-Residence in 1980.
During his high-school teaching years, Hassler married and fathered three children. His first marriage lasted 25 years. He had two more marriages; the last was to Gretchen Kresl Hassler.
In 1994, Hassler was diagnosed with progressive supranuclear palsy (PSP), a disease similar to Parkinson's. It caused vision and speech problems, as well as difficulty walking, but he was able to continue writing. He was reported to have finished a novel just days before his death. Hassler died in 2008, at the age of 74, at Methodist Hospital in St. Louis Park, Minnesota.