The Prime Minister said the changes will allow people to “get back to more of the things they have missed” since the health crisis began after rising infection rates appeared to have “levelled off”.
However Mr Johnson also introduced tougher penalties for repeatedly failing to wear face masks in public places.
Fines will double each time someone is found in breach of the rules, up until a maximum of £3,200. Hairdressers will also now be required to wear surgical face masks.
Mr Johnson also announced that people hosting an illegal rave or gathering of more than 30 people will now be issued spot fines. Government sources on Wednesday night said this could be up to £10,000.
Last weekend, West Midlands Police shut down 125 parties and raves, and closed a pub, to stop illegal gatherings and anti-social behaviour.
Face coverings are mandatory for most people in shops and supermarkets and on public transport. The rules also cover buying takeaways in cafes and shops.
From last week they have also been required in museums, galleries, and places of worship.
Anyone failing to wear a face covering while shopping has been subject to a fine of up to £100, or £50 if paid within 14 days.
All the measures that were put on hold two weeks ago by the Prime Minister will now be reinstated from this Saturday.
This will apply across England, except for areas under local lockdown.
Mr Johnson had postponed the changes, which were meant to come in on August 1, amid concerns over a second wave of coronavirus.
At the time, the Chief Medical Officer said the country had “probably reached near the limit or the limits” of what can be done to reopen society.
Wedding receptions of up to 30 people will now be allowed from Saturday, as will the reopening of casinos, bowling alleys and skating rinks.
Beauty salons, tattoo studios and spas will be able to offer all close “ services and treatments”.
All staff offering close contact services, including hairdressers, will now be required to wear a surgical face mask in addition to a visor, following concerns the visors did not offer enough protection.
On Wednesday night Mr Johnson said he “will not hesitate to put on the brakes if required, or to continue to implement local measures to help to control the spread of the virus.”
He added: “At every stage I have said our plan to reopen society and the economy is conditional and that it relies on continued progress against the virus.”
Plans to start indoor performances with socially-distanced audiences and pilots of larger gatherings in sports venues and conference centres will also resume.
This weekend’s final of the World Snooker Championship in Sheffield will be the first pilot event. Allowing spectators at sporting events is planned for October 1.
Pilots at the Goodwood races, the world snooker final and county cricket games earlier this month were suspended after Mr Johnson put the brakes on easing lockdown measures after concerns over a second wave.
In addition, indoor play and soft play centres will reopen, provided they introduce coronavirus-secure measures.
Commenting on the new tougher fines, Home Secretary Priti Patel said: “I will not stand by and see these sacrifices undermined by a small minority of senseless individuals.
“These measures send a clear message – if you don’t cooperate with the police and if you put our health at risk, action will follow.”
Mr Johnson added: “We must remain focused and we cannot be complacent. That is why we are strengthening the enforcement powers available to use against those who repeatedly flout the rules.”