The 2007 Bernard Matthews H5N1 outbreak was an occurrence of avian influenza in England caused by the H5N1 subtype of Influenza virus A that began on 30 January 2007. The infection affected poultry at one of Bernard Matthews' farms in Holton in Suffolk. It was the third instance of H5N1-subtype detected in the United Kingdom and a range of precautions were instituted to prevent spread of the disease including a large cull of turkeys, the imposition of segregation zones, and a disinfection programme for the plant.
The cause of the outbreak was not determined. However, it was considered significant that Bernard Matthews regularly transports turkeys and turkey products between the UK and its plant in Hungary, and that the H5N1 strains previously found in Hungary, and those found at Suffolk, were effectively genetically identical.