Randolph John Seiler (July 1, 1946 – April 17, 2023) was an American attorney and veteran serving as the chair of the Democratic Party of South Dakota from 2019-2023.

[2] He returned to the United States and graduated cum laude with a Bachelor of Science in Criminal Justice from the University of Nebraska Omaha.

Seiler was appointed by then-Governor Dick Kneip to serve as the director of the South Dakota Division of Law Enforcement Assistance.

During the last two of his four years in that position, he pursued a Master of Arts degree with an emphasis in Public Administration before devoting himself full-time to the University of South Dakota School of Law graduating in 1980.

During that time, he also served as the Campbell County Deputy States Attorney and Special Judge for the Cheyenne River Sioux Tribe.

After 13 years in private practice, Seiler began his distinguished tenure as Assistant United States Attorney for the District of South Dakota, representing the United States in the prosecution of federal felony criminal law violations including murder, rape, child sexual abuse, robbery, domestic violence, aggravated assault, civil rights, public corruption, white collar crime, and other major offenses.

On March 12, 2015, Seiler was nominated by then President Barack Obama to serve as the United States Attorney for the District of South Dakota.

"[6] Seiler also took "a more proactive and aggressive stance"[7] in 2017 by establishing “Walk-In Wednesday,” a program that opened an office in Pine Ridge staffed once a week with a federal prosecutor.

Designed to allow citizens to more easily communicate with the office concerning crime on the reservation, inquiries about existing cases, or to obtain any information which might be sought by residents.