Professor John Newton, Public Health England's director of health, said that in light of the "unprecedented" pandemic sweeping the globe, "there has never been a more important time to stop smoking, not only for your own health but to protect those around you".
PHE said that smoking can cause damage to the lungs and airways, and Covid-19 attacks the respiratory system.
Officials also point to a "small but highly impactful" survey from China which finds that smokers with Covid-19 are 14 times more likely to develop severe disease.
The study looked at the factors which led to the progression of Covid-19 pneumonia in patients at three hospitals in Wuhan, in the Hubei province of China, where the first cases of coronavirus were detected late last year.
A "history of smoking" was among the factors which were identified by the study which took place between December 30 last year and January 15.
Age, maximum body temperature on admission and respiratory failure were among other notable factors, according to the study, which was published in the Chinese Medical Journal.
These results "can be used to further enhance the ability of management of Covid-19 pneumonia", it concluded.
It has been reported that more than 3,300 people have died of Covid-19 in China.
PHE also says the virus is given an easy route of entry by the repetitive hand to mouth movement used by smokers.
Prof Newton told smokers that "it is never too late to quit, no matter your age" and the body will continue to repair the longer you stay smoke-free.
The elimination of carbon monoxide from the body is among the immediate benefits of quitting smoking.
People should find that their lungs start to clear out mucus and other smoking debris, PHE says.
Breathing becomes easier as bronchial tubes begin to relax after 72 hours of quitting smoking and blood circulation improves, making physical activity like walking and running easier within 12 weeks of giving up the habit.