According to the Crown Estate, the virus has been detected in Obelisk Pond and Cow Pond as well as the lake at Virginia Water.
According to the park's website, the situation is being monitored and visitors are being urged to keep to the footpaths.
Dog owners are being asked to keep their pets on leads around bodies of water.
Windsor Great Park is also advising people not to pick up or touch wild birds or feathers and to avoid touching surfaces contaminated with wild bird droppings.
Anyone who finds any dead or sick birds in the park is asked to call the Duty Warden with your location on 07833 543025, or email email@example.com.
In the United Kingdom, there have been 162 confirmed cases of highly pathogenic avian influenza (HPAI) H5N1 since 1 October 2022:
143 cases in England
15 cases in Scotland
3 cases in Wales
1 case in Northern Ireland
There have been 278 cases of (HPAI) H5N1 in England since the H5N1 outbreak started in October 2021.
Find details of all bird flu cases and disease zones in England here.