Special Investigations Unit or Special Investigation Unit may refer to:
Special Investigations Unit (Ontario), a provincial police oversight agency in Canada CNN Special Investigations Unit, an investigative documentary on CNN Multnomah County Sheriff's Office's Special Investigations Unit New York State Office of Tax Enforcement's Special Investigations Unit S.I.U. (film), 2011 Korean action film White House Plumbers, covert White House Special Investigations Unit during the Nixon presidency Special Investigation Team (India)
See also Special Investigating Unit, South African law enforcement agency SIU (disambiguation) Special Investigations Bureau (disambiguation) Special Investigations Division (disambiguation) Office of Special Investigations (disambiguation) Special Investigations Section (disambiguation) Special Investigations (disambiguation)