William Marshall Tredway (August 24, 1807 - May 1, 1891) was a U.S. Representative from Virginia.
Born near Farmville in Prince Edward County, Virginia, Tredway completed preparatory studies. He was graduated from Hampden-Sydney College, Prince Edward County, Virginia, in 1827. He studied law. He was admitted to the bar in 1830 and commenced practice in Danville, Virginia.
Tredway was elected as a Democrat to the Twenty-ninth Congress (March 4, 1845-March 3, 1847). He was an unsuccessful candidate for reelection in 1846 to the Thirtieth Congress. He served as delegate to the Democratic State convention in 1850. He served as member of the secession convention of Virginia in 1861. He served as judge of the circuit court of Virginia 1870-1879. He resumed the practice of law in Chatham, Virginia, and died there May 1, 1891. He was interred in Chatham Cemetery.