Yes. Smoking is now banned in all enclosed and semi-enclosed public places in the whole of the UK, and it is your employer’s responsibility to make sure that the law is respected on its premises.
Hotels, inns, hostels, guesthouses and members' clubs that provide sleeping accommodation are allowed to designate individual guest bedrooms for smokers, but smoking should not be allowed in any other areas.
There is also an offence of 'failing to prevent' smoking in an enclosed public place. If you work in a pub, bar or hotel you may well have to challenge customers who smoke indoors. The person who 'manages or controls' the premises has the ultimate responsibility, so make sure you have guidance from your employer on how to handle such situations.
After repeated calls by the Prison Officers Association for all prisons to be smoke-free workplaces, all prisons in Wales have been operating a smoke-free policy since January 2016. In England meanwhile, the Court of Appeal ruled in 2016 in favour of the government by declaring that the ban on smoking in public places does not apply to state prisons. This has allowed the government to roll out a smoking ban gradually.
In Scotland, prisoners can smoke in their cells and in some outdoor areas but prison staff are banned from smoking anywhere. In Northern Ireland smoking is permitted in prison cells and certain open spaces.
See our Smoking section for more advice.