John Sylvanus Thompson (8 March 1889 – 1963) was an American pianist, composer, and educator.
In July, 1909, Thompson applied for a passport in preparation for touring Europe as a concert pianist.
Once there, however, due to health issues and unrest leading up to World War I, he returned to the United States in April 1914.
Thompson moved to Philadelphia to teach piano and met a writer, Loretta Katherine Foy, three years his junior, who was residing with her widowed mother.
They relocated to Kansas City, Missouri, where Thompson worked as a piano teacher in a music school.