Avian influenza of the H5N8 strain was confirmed at a turkey fattening premises near Northallerton on Saturday, November 28.
All 10,500 birds at the farm will be humanely culled to limit the spread of the disease.
A 3km and 10km Temporary Control Zone has been put in place around the infected site to limit the risk of the disease spreading.
Public Health England (PHE) advises that the risk to public health from the virus is very low and the Food Standards Agency advises that avian influenzas pose a very low food safety risk for UK consumers. Properly cooked poultry and poultry products, including eggs, are safe to eat.
Chief Veterinary Officer, Christine Middlemiss, said:
Avian flu has been confirmed at a commercial turkey fattening farm near Northallerton, North Yorkshire. Immediate steps have been taken to limit the risk of the disease spreading and all the remaining turkeys at the farm will be culled.
"Public Health England has confirmed that the risk to public health is very low and the Food Standards Agency advises that bird flu poses a very low food safety risk for UK consumers.
"Bird keepers should remain alert for any signs of disease, report suspected disease immediately and ensure they are maintaining good biosecurity on their premises.
"We are urgently looking for any evidence of disease spread associated with this farm to control and eliminate it."
Public risk is 'very low'
Dr Gavin Dabrera, Consultant in Acute Respiratory Infections at PHE said:
To date the World Health Organisation has never confirmed any cases of H5N8 in humans and the risk to the public is considered very low.
"As a precaution the local Health Protection Team will offer routine health advice to those working on the farm. We will work with Defra to monitor the situation closely."
A Food Standards Agency spokesperson said:
"We advise that, on the basis of the current scientific evidence, avian influenza poses a very low food safety risk for UK consumers.
Properly cooked poultry and poultry products, including eggs, remain safe to eat.
A detailed investigation is in progress to determine the most likely source of this outbreak.
There is not anticipated to be any impact on the supplies of turkeys or other birds over Christmas.