This is a list of films which have placed number one at the weekend box office in Canada during 2004.
| # | Weekend End Date | Film | Weekend Gross (millions) | Notes | | 1 | 2004|January|4}} | The Return of the King | $4.38 |
| 2 | 2004|January|11}} | The Lord of the Rings: The Return of the King | $2.32 |
| 3 | 2004|January|18}} | Along Came Polly | $2.31 |
| 4 | 2004|January|25}} | The Butterfly Effect | $1.48 |
| 5 | 2004|February|1}} | The Butterfly Effect | $1.12 | You Got Served was #1 in America. |
| 6 | 2004|February|8}} | The Butterfly Effect | $0.98 | Back in Business was #1 in America. |
| 7 | 2004|February|15}} | 50 First Dates | $4.18 |
| 8 | 2004|February|20}} | 50 First Dates | $2.13 |
| 9 | 2004|February|29}} | The Passion of the Christ | $4.27 |
| 10 | 2004|March|7}} | The Passion of the Christ | $2.87 |
| 11 | 2004|March|14}} | The Passion of the Christ | $1.87 |
| 12 | 2004|March|21}} | Dawn of the Dead | $1.82 |
| 13 | 2004|March|28}} | Monsters Unleashed | $2.23 |
| 14 | 2004|April|4}} | Hellboy | $2.14 |
| 15 | 2004|April|11}} | Hellboy | $1.13 | The Passion of the Christ was #1 in America. |
| 16 | 2004|April|18}} | Volume 2 | $2.74 |
| 17 | 2004|April|25}} | 13 Going on 30 | $1.78 | Man on Fire was #1 in America. |
| 18 | 2004|May|2}} | Mean Girls | $2.16 |
| 19 | 2004|May|9}} | Van Helsing | $3.81 |
| 20 | 2004|May|16}} | Troy | $5.21 |
| 21 | 2004|May|23}} | Shrek 2 | $9.78 | Shrek 2 had the highest weekend debut of 2004. |
| 22 | 2004|May|30}} | Shrek 2 | $5.93 |
| 23 | 2004|June|6}} | Harry Potter and the Prisoner of Azkaban | $8.58 |
| 24 | 2004|June|13}} | Harry Potter and the Prisoner of Azkaban | $4.19 |
| 25 | 2004|June|20}} | Harry Potter and the Prisoner of Azkaban | $2.21 | A True Underdog Story was #1 in America. |
| 26 | 2004|June|27}} | Fahrenheit 9/11 | $2.52 |
| 27 | 2004|July|4}} | Spider-Man 2 | $8.81 |
| 28 | 2004|July|11}} | Spider-Man 2 | $3.85 |
| 29 | 2004|July|18}} | I, Robot | $2.57 |
| 30 | 2004|July|25}} | The Bourne Supremacy | $4.35 |
| 31 | 2004|August|1}} | The Village | $2.94 | |
| 32 | 2004|August|8}} | Collateral | $2.21 |
| 33 | 2004|August|15}} | Alien vs. Predator | $2.85 |
| 34 | 2004|August|22}} | The Beginning | $1.04 |
| 35 | 2004|August|29}} | Hero | $2.09 |
| 36 | 2004|September|5}} | Hero | $1.42 |
| 37 | 2004|September|12}} | Apocalypse | $2.25 |
| 38 | 2004|September|19}} | Sky Captain and the World of Tomorrow | $1.21 |
| 39 | 2004|September|26}} | The Forgotten | $2.05 |
| 40 | 2004|October|3}} | Shark Tale | $2.78 |
| 41 | 2004|October|10}} | Shark Tale | $2.38 |
| 42 | 2004|October|17}} | Shark Tale | $1.94 |
| 43 | 2004|October|24}} | The Grudge | $3.23 |
| 44 | 2004|October|31}} | The Grudge | $2.18 |
| 45 | 2004|November|7}} | The Incredibles | $4.19 |
| 46 | 2004|November|14}} | The Incredibles | $3.57 |
| 47 | 2004|November|21}} | The SpongeBob SquarePants Movie | $2.53 | National Treasure was #1 in America. |
| 48 | 2004|November|28}} | Alexander | $1.49 | National Treasure was #1 in America. |
| 49 | 2004|December|5}} | National Treasure | $1.14 | National Treasure reached #1 in its third weekend of release. |
| 50 | 2004|December|12}} | Ocean's Twelve | $3.19 |
| 51 | 2004|December|19}} | Ocean's Twelve | $1.84 | Lemony Snicket's A Series of Unfortunate Events was #1 in America. |
| 52 | 2004|December|26}} | Meet the Fockers | $2.43 |