The 3D film, which features the voices of Kelly Macdonald, Emma Thompson and Billy Connolly, takes in £2.3 million to hold off competition from comedy Ted and The Bourne Legacy.
The Dark Knight Rises charts at number four as it crosses the £52 million mark in the UK. Christopher Nolan's Batman trilogy closer is now the highest-grossing film in Britain for 2012, surpassing The Avengers's £51.8 million haul.
Keith Lemon The Film rounds out the top five with a £1.1 million box office total.
Elsewhere, the chart sees new entries in the form of Farrelly brothers comedy The Three Stooges and documentary The Imposter. The latter pulls in an impressive £252,170 from its 49 locations.
The UK box office top ten in full:
1. (1) Brave - £2,371,691
2. (3) Ted - £1,692,883
3. (2) The Bourne Legacy - £1,596,289
4. (5) The Dark Knight Rises - £1,378,717
5. (-) Keith Lemon The Film - £1,196,310
6. (4) The Expendables 2 - £1,028,904
7. (-) The Three Stooges - £509,324
8. (7) Diary of a Wimpy Kid: Dog Days - £424,206
9. (8) Ice Age 4: Continental Drift - £331,851
10. (-) The Imposter - £252,170
Photo gallery - Pixar at the movies: