John Luman Smith (born June 5, 1969) is an American attorney who has served in the United States Department of Justice as an assistant U.S. attorney, acting U.S. attorney, and head of the department's Public Integrity Section. He was also the chief prosecutor at the Kosovo Specialist Chambers, an international tribunal at The Hague tasked with investigating and prosecuting war crimes in the Kosovo War. He served as a Special Counsel for the Department of Justice from November 18, 2022 until his resignation on January 10, 2025.

In November 2022, attorney general Merrick Garland appointed Smith an independent special counsel, responsible for overseeing two preexisting Justice Department criminal investigations into former president Donald Trump, three days after Trump announced his 2024 presidential campaign: one regarding Trump's role in the January 6 U.S. Capitol attack, and the other into alleged mishandling of government records, including classified documents. The documents case resulted in a 37-count indictment of Trump in June 2023 to which three counts were later added in July. In August, the January 6 case resulted in an indictment on four charges.

The classified documents case was dismissed by judge Aileen Cannon in July 2024, on the grounds that Smith was unlawfully appointed as special counsel. Smith's office initially appealed the ruling, but ultimately abandoned the appeal after Trump won the 2024 US presidential election. The election subversion case was dismissed by judge Tanya Chutkan in November 2024, on the grounds that the Office of Legal Counsel held that Trump as President-elect could not be charged consistent with the Constitution.