The chief mouser will continue to live at the famous residence after Theresa May becomes Prime Minister.
A Cabinet Office spokeswoman said: “It’s a civil servant’s cat and does not belong to the Camerons - he will be staying,” the Press Association reports.
The brown and white tabby, who was re-homed from Battersea Dogs and Cats Home in 2011, was said to have a “strong predatory drive” that suggested he would be well-suited to the task of rat catching.
Cameron welcomed the cat’s arrival, and said he would make a “great addition” to the Number 10 team.
Larry was the first cat to hold the appointment since stalwart ratter Humphrey was retired in 1997.
Humphrey was succeeded for a short period by Sybil, the pet of then chancellor Alistair Darling, in 2007 - but the renowned mouser failed to settle and returned to Scotland.
The Foreign Office appointed Palmerston, a moggy, in April to keep pests in Whitehall at bay.
An unofficial Larry the cat twitter account welcomed the news and asked for recommendations of a new cat groomer.
The BBC's political editor Laura Kuenssberg filmed an exclusive clip of Larry having a fierce reshuffle debate with Palmerston on Monday night.
May is set to become the next Tory leader and British prime minister after Andrea Leadsom withdrew from the race on Monday.
The Home Secretary said she had the “strong, proven leadership to steer us through what will be difficult and uncertain economic and political times”, adding “Brexit means Brexit, and we are going to make a success of it”.
“We are going to unite our country...We need a strong, new positive vision for the future of our country, a vision of a country that works not for the privileged few but that works for everyone one of us.”