(Thomas) Hugh Pennington FRCPath, FRCP (Edin) FMedSci, FRSE (born 19 April 1938 in Hendon, Middlesex) is emeritus professor of bacteriology at the University of Aberdeen, Scotland. Outside academia, he is best known as the chair of the Pennington Group enquiry into the Scottish Escherichia coli outbreak of 1996 and as Chairman of the Public Inquiry into the 2005 Outbreak of E. coli O157 in South Wales.
Pennington was educated at Lancaster Royal Grammar School in Lancashire, England. Pennington obtained his MBBS degree in 1962, and his PhD in 1967, both from St Thomas's Hospital Medical School, which became part of United Medical and Dental Schools of Guy's and St Thomas' Hospitals in 1982, and has been known as King's College London School of Medicine and Dentistry since 2005.
He spent a year at the University of Wisconsin–Madison before moving to the Glasgow Institute of Virology in 1969, where he researched vaccinia, smallpox and other viruses. He was appointed Chair of Bacteriology at the University of Aberdeen in 1979, where he remained until his retirement in 2003. His research focused on improved bacteria typing, or "fingerprinting", methods. He was dean of the medical school between 1987 and 1992. Pennington was also awarded a higher doctorate, i.e. Dsc.