William Medcalf Kinsey (October 28, 1846 – June 20, 1931) was a U.S. Representative from Missouri.

He was admitted to the bar in 1872 and commenced practice in Muscatine County, Iowa, the same year.

He moved to St. Louis, Missouri, in 1875 and engaged in the practice of law.

During the First World War, he was chairman of the draft examining board in Carondelet.

He was interred in Sunset Hill Burial Park, St. Louis County, Missouri.