An excellent weekend gross of £9.5 million sees the film enter ahead of the weeks other big film Independence Day Resurgence.
Despite having the connection to the Despicable Me franchise The Secret Life of Pets for a new franchise makes an very good debut, in comparison it is far higher that the first Despicable Me but lower than the franchises other films.
With the summer holidays in the coming weeks this could have staying power, and there is little competition until mid July.
Also new this week is Independence Day Resurgence which makes its debut at number 2 with just over £5 million, its been 20 years but the original debuted to £16 million.
Last weeks top film, The Conjuring 2 The Enfield Case, falls to number 3 with a total gross of £7.7 million after a £1.5 million second weekend.
The Jungle Book is once again the top total grossing film on the box office with £45.6 million and the longest run on the box office with 11 weeks.
Historical charts
A year ago - Minions made its debut at the top knocking Jurassic World to the runner up spot.
Five years ago - Paul Feig's Bridesmaids was the new film making its debut at the top while Kung Fu Panda 2 fell to number 2.
Ten years ago - The Fast and The Furious Tokyo Drift stayed at the top of the box office and The Lake House was the top new film at number 2.
Fifteen years ago - Evolution was the top new film at number 1, it knocked Pearl Harbour down to number 2.
Twenty years ago - New at the top was The Rock with Spy Hard being knocked off the top right down to number 4.
Twenty five years ago - The Silence of The Lambs stayed at the top of the box office while The Pope Must Die came in new at number 2.
