James Allen Williamson (born May 27, 1951) is an American attorney and Republican politician from the U.S. state of Oklahoma. Williamson served in the Oklahoma House of Representatives from 1980 to 1986 and in the Oklahoma Senate from 1996 to 2008. From 1998 to 2002 he served as Assistant Republican Floor Leader, and then as Floor Leader from 2003 to 2004. He is currently serving on President pro tempore of the Oklahoma Senate Brian Bingman's leadership staff as senior policy advisor and legal counsel.