Welsh pubs, bars, restaurants and cafes will be subject to a 6pm curfew and banned from serving alcohol from 4 December.
First minister Mark Drakeford announced the rules today to tackle a rise in coronavirus cases across the country.
Businesses can remain open after 6pm for takeaway or delivery but will be unable to sell alcohol at any time of the day, he said.
Cinemas, bowling alleys and other indoor entertainment venues will also have to close from Friday.
Drakeford said without action there could be between 1,000 and 1,700 preventable deaths in Wales over the winter.
The Welsh government will review the restrictions by 17 December and then every three weeks.
A £340m fund is being made available for businesses, which the first minister described as "the most generous package of financial assistance anywhere in the UK".
It includes £180m for the hospitality, tourism and leisure sectors, including grants of up to £100,000 for small to medium enterprises (SMEs) and £150,000 for larger businesses based on the number of staff and operating costs.
An additional £160m is being made available for firms on the non-domestic rating list. Hospitality businesses and their supply chains will receive payments of between £3,000-£5,000 through their local authorities.
Drakeford said payments would be made "as quickly as possible and before Christmas".
He added: "I recognise how hard hospitality and visitor sectors have worked to comply with the regulations and to protect customers.
"I am very grateful for everything the sector has done I know that these new restrictions will be difficult coming at one of the busiest times of the year.
"But it is a simple fact that we continue to face a virus that is moving incredibly quickly across Wales, that will exploit every opportunity when we spend time with one another."
Hospitality venues in Wales have only been able to reopen since 9 November when the country's 17-day ‘firebreak' lockdown ended.
Drakeford said travel restrictions between England and Wales would be looked at again this week with the lifting of the English national lockdown on 2 December.