Rees Gephardt "Steamboat" Williams (January 31, 1892 – June 29, 1979) was a baseball player for the 1914 and 1916 St. Louis Cardinals.
Williams was born in Cascade, Montana, and was the first Montana-born player in Major League Baseball history. He batted left-handed and threw right-handed. He was 5 ft 11 in (1.80 m) tall and weighed 170 pounds (77 kg). He died in Deer River, Minnesota.