Health minister Stoycho Katsarov confirmed the move on Friday (16 July), effective from Monday (19 July) citing concerns about the rising number of Covid cases in the UK.
Bulgaria also added Spain, Cyprus, Fiji and Kuwait to its red list.
It means only Bulgarian citizens, long-term residents and their immediate family will be able to enter the country from the UK.
The decision to red list the UK came just days after the UK government placed Bulgaria on its green list.
