Lawrence Leroy Piersol (born 1940) is a United States federal judge.
Born in Vermillion, South Dakota, Piersol received a B.A. from the University of South Dakota in 1962 and a J.D. from the University of South Dakota School of Law in 1965. He was in the United States Army, JAG Corps from 1965 to 1968. He was in private practice in Sioux Falls, South Dakota from 1968 to 1993.
On August 6, 1993, Piersol was nominated by President Bill Clinton to a seat on the United States District Court for the District of South Dakota vacated by Donald J. Porter. Piersol was confirmed by the United States Senate on November 20, 1993, and received his commission on November 22, 1993. He served as chief judge from 1999 to 2005.