This is a list of Belgian municipalities by population:

1. Brussels (999,899) (counting the capital region as one municipality)
2. Antwerp (455,148)
3. Ghent (229,344)
4. Charleroi (200,608)
5. Liège (185,488)
6. Bruges (117,025)
7. Namur (106,213)
8. Mons (91,185)
9. Leuven (89,777)
10. Mechelen (76,981)
11. Aalst (76,852)
12. La Louvière (76,784)
13. Kortrijk (73,984)
14. Hasselt (69,127)
15. Sint-Niklaas (68,820)
16. Ostend (68,273)
17. Tournai (67,341)
18. Genk (63,550)
19. Seraing (60,579)
20. Roeselare (55,273)
21. Verviers (52,804)
22. Mouscron (52,290)
23. Beveren (45,243)
24. Dendermonde (43,043)
25. Beringen (40,396)
26. Turnhout (39,455)
27. Dilbeek (39,058)
28. Heist-op-den-Berg (37,868)
29. Sint-Truiden (37,722)
30. Lokeren (37,304)
31. Brasschaat (37,165)
32. Herstal (36,549)
33. Vilvoorde (36,466)
34. Braine-l'Alleud (36,463)
35. Maasmechelen (36,032)
36. Waregem (35,977)
37. Châtelet (35,538)
38. Ninove (35,039)
39. Ieper (35,021)
40. Geel (34,444)
41. Halle (34,316)
42. Knokke-Heist (33,777)
43. Grimbergen (33,362)
44. Schoten (33,190)
45. Lier (32,821)
46. Mol (32,356)
47. Binche (32,227)
48. Menen (32,141)
49. Tienen (31,782)
50. Wavre (31,693)
51. Evergem (31,657)

Source

INS, demographical statistics (2004) [1]