William B. Pine (December 30, 1877 - August 25, 1942) was a United States Senator from Oklahoma. Born in Bluffs, Illinois, he attended the public schools, taught school three years, and was employed as a salesman of harvesters. He moved to Chanute, Kansas and was employed in the oil producing business; he moved to Oklahoma in 1904 and continued in the oil industry. In 1909 he located in Okmulgee, Oklahoma where he eventually became extensively engaged in the production of oil.
Pine was elected as a Republican to the U.S. Senate and served from March 4, 1925, to March 3, 1931; he was unsuccessful candidate for reelection in 1930, after which he resumed his former business pursuits. He was an unsuccessful candidate for governor in 1934. He died in Okmulgee in 1942; at the time of his death, he was the Republican nominee for the U.S. Senate. Interment was in Okmulgee Cemetery.