Frank Theis was born in Kansas City, Missouri in 1890 or 1891. His father worked in wheat but tried to steer his son to a law career, and Theis finished his law degree at the University of Kansas.

However, after finishing school, Theis began working at Simonds-Sheilds-Lonsdale of Kansas City, a firm that owned grain elevators and made money through buying wheat and selling it to millers. Eventually the company changed its name to Simonds-Sheilds-Theis, and Theis became its president in 1935.

In 1931, Theis became president of the Kansas City Board of Trade. He served as a special representative of the U.S. Secretary of Agriculture in Argentina in 1934 as well as a grain marketing consultant for the government in 1933-1934 and became known by the nickname "Mr. Wheat."

Theis took an interest in local civic affairs, serving on the board of park commissioners for 15 years as well as on mnay local charitable boards. During World War II he served on the War Food administration committee.

Frank Theis married Rachael; they had two children, Mary (Theis) Kimball and William C., who followed his father into the grain industry. Frank Theis died in November 1965. Theis Park near the Country Club Plaza and the Nelson-Atkins Museum of Art in Kansas City is named after him.