This is a list of films which placed number one at the weekly box office in the United States during 1945 per Variety's weekly National Boxoffice Survey. The results are based on a sample of 20-25 key cities and therefore, any box office amounts quoted may not be the total that the film grossed nationally in the week.
| The Bells of St. Mary's became the highest-grossing film of the year despite not reaching #1. |
| Date | Title | Ref |
|---|---|---|
| January 3 | Thirty Seconds Over Tokyo | [1] |
| January 10 | Meet Me in St. Louis | [1] |
| January 17 | [1] | |
| January 24 | [1] | |
| January 31 | National Velvet | [1] |
| February 7 | [2] | |
| February 14 | [2] | |
| February 21 | [2] | |
| February 28 | [2] | |
| March 7 | [3] | |
| March 14 | [3] | |
| March 21 | [3] | |
| March 28 | [3] | |
| April 4 | [4] | |
| April 11 | Brewster's Millions | [4] |
| April 18 | [4] | |
| April 25 | Son of Lassie | [4] |
| May 2 | [5] | |
| May 9 | The Valley of Decision | [5] |
| May 16 | [5] | |
| May 23 | [5] | |
| May 30 | Thrill of a Romance | [5] |
| June 6 | [6] | |
| June 13 | [6] | |
| June 20 | [6] | |
| June 27 | [6] | |
| July 4 | [7] | |
| July 11 | [7] | |
| July 18 | [7] | |
| July 25 | [7] | |
| August 1 | [8] | |
| August 8 | [8] | |
| August 15 | Son of Lassie | [8] |
| August 22 | [8] | |
| August 29 | [8] | |
| September 5 | [9] | |
| September 12 | [9] | |
| September 19 | [9] | |
| September 26 | [9] | |
| October 3 | Rome, Open City | [10] |
| October 10 | Week-End at the Waldorf | [10] |
| October 17 | [10] | |
| October 24 | [10] | |
| October 31 | The Clock | [10] |
| November 7 | [11] | |
| November 14 | [11] | |
| November 21 | Mildred Pierce | [11] |
| November 28 | [11] | |
| December 5 | [12] | |
| December 12 | [12] | |
| December 19 | [12] | |
| December 26 | [12] |