More than 100,000 people have booked to be at Tuesday night’s sold-out firework extravaganza in the capital.
But the Metropolitan Police told anyone who had not got a ticket to stay away.
In a statement, the force said: “If visitors do not have a ticket, entry will not be permitted to the event, so the advice is to watch the fireworks from the comfort of your home.”
Mass celebrations are to be held across the UK to usher in 2020.
Large firework displays and light shows will take place in cities including Edinburgh, Cardiff, Manchester, Newcastle and Nottingham.
In London itself, some 12,000 fireworks are set to be exploded when the clock strikes midnight.
Roughly 2,000 of those will be blasted from the London Eye with the rest fired from barges moored in the Thames.
One theme of the celebrations is expected to be the city’s role in hosting seven Euro 2020 football games next summer, including the tournament’s final.
Sadiq Khan, Mayor of London, said: “Once again, we will show that London is open to the world as we welcome sports fans and football stars from all over Europe.”
In Edinburgh, meanwhile, thousands of people will attend a Hogmanay street party featuring acts Mark Ronson, Marc Almond and Idlewild.
Weather-wise, the evening is set to be largely dry with temperatures in Scotland, Northern Ireland and parts of northern England forecast to be around 1C, and 5C in the rest of country, according to the Met Office.