Samuel Byrns (March 4, 1848 – July 9, 1914) was a U.S. Representative from Missouri.

Born on a farm in Jefferson County, Missouri, Byrns studied law.

He was admitted to the bar in 1872 and commenced practice in Hillsboro, Missouri.

He served as member of the Democratic State central committee 1886–1888.

He resumed the practice of his chosen profession in De Soto, Missouri, where he died on July 9, 1914.