The action movie - starring Jeremy Renner, Rachel Weisz and Edward Norton - leads the standings having opened with receipts of just over AU$4.2 million across 435 screens.
The Sapphires holds the number two slot, while The Dark Knight Rises slips to number three, as its total takings in Australia edge towards the AU$40 million mark.
The only other new entry in this week's top ten is Salman Khan's Ek Tha Tiger, which enters the chart in seventh place.
The Australian box office top ten for the period August 16 to 19 (all takings shown in Australian dollars):
1. (-) The Bourne Legacy - $4,200,061
2. (2) The Sapphires - $1,964,796
3. (1) The Dark Knight Rises - $1,605,928
4. (3) The Campaign - $1,058,079
5. (4) Magic Mike - $720,200
6. (5) Step Up 4: Miami Heat - $679,445
7. (-) Ek Tha Tiger - $320,518
8. (6) Ted - $277,473
9. (8) Ice Age 4: Continental Drift - $191,472
10. (7) Abraham Lincoln: Vampire Hunter - $163,348
Watch a trailer for The Bourne Legacy below:
