Children who were born on or after January 1 2009, will face a lifelong ban on buying cigarettes after the Tobacco and Vapes Bill cleared Parliament.
Both the Commons and Lords have settled on a final draft of the legislation, which is designed to stop people aged 17 or younger from ever taking up smoking.
When it receives royal assent, ministers will also get new powers to regulate tobacco, vaping and nicotine products, including their flavours and packaging.
Health minister Baroness Merron told the Lords on Monday: “This afternoon marks the end of this Bill’s journey throughout Parliament.
“It is a landmark Bill, it will create a smoke-free generation.
“It is, in fact, the biggest public health intervention in a generation and I can assure all noble Lords it will save lives.”
Lord Naseby, a Conservative former MP, said the Tobacco and Vapes Bill “does upset a great many people in that industry”, including retailers.
He added: “What we really need is a proper understanding of how we educate people not to take up smoking.”
Responding to Lord Naseby, Lady Merron said: “I can overall assure Lord Naseby, as I’ve done on a number of occasions, about how closely we have worked with retailers, and we will continue to do so.”