Organisers described the spruce as “one of the world’s most famous Christmas trees” representing “friendship between cities and countries, peace, and solidarity.”
It will be decorated with energy-efficient lightbulbs, hanging vertically in traditional Norwegian fashion.
The British ambassador to Norway, Jan Thompson, said: “It isn’t Christmas in the UK until the Trafalgar Square tree arrives.”
She added that the tree had “brought joy to generations of Londoners”, and said: “For many people visiting London it is as essential to see the Norwegian tree as to go Christmas shopping in Oxford Street or catch a show in the West End.”