Thomas Hugh Pennington, CBE, FRCPath, FRCP (Edin), FMedSci, FRSE (born 19 April 1938) 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.