Domestic Box Office For April 2021
Key:Estimated
| Rank | Release | Gross | Max Th | Opening | % of Total | Open Th | Open | Close | Distributor |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Demon Slayer: Kimetsu no Yaiba - The Movie: Mugen Train | $49,505,008 | 2,087 | $21,234,994 | 42.9% | 1,614 | Apr 23 | - | FUNimation Entertainment |
| 2 | Mortal Kombat | $42,326,031 | 3,114 | $23,302,503 | 55.1% | 3,073 | Apr 23 | - | Warner Bros. |
| 3 | The Unholy | $15,532,137 | 2,057 | $3,153,456 | 20.3% | 1,850 | Apr 2 | - | Screen Gems |
| 4 | Separation | $4,509,143 | 1,911 | $1,800,162 | 39.9% | 1,751 | Apr 30 | - | Open Road Films (II) |
| 5 | The Girl Who Believes in Miracles | $3,163,362 | 1,012 | $546,000 | 17.3% | 640 | Apr 2 | - | Atlas Distribution Company |
| 6 | Voyagers | $3,149,935 | 1,996 | $1,379,988 | 43.8% | 1,972 | Apr 9 | - | Lionsgate |
| 7 | Together Together | $1,437,938 | 665 | $532,773 | 37.1% | 665 | Apr 23 | - | Bleecker Street Media |
| 8 | In the Earth | $1,113,723 | 571 | $505,723 | 45.4% | 547 | Apr 16 | - | Neon |
| 9 | Four Good Days | $837,849 | 489 | $298,358 | 35.6% | 298 | Apr 30 | - | Vertical Entertainment |
| 10 | 2021 Oscar Nominated Short Films: Live Action | $443,050 | 184 | $81,113 | 18.3% | 157 | Apr 2 | - | Magnolia Pictures |
| 11 | Limbo | $224,405 | 213 | $84,710 | 37.7% | 208 | Apr 30 | - | Focus Features |
| 12 | The Resort | $191,996 | 114 | $88,831 | 46.3% | 114 | Apr 30 | - | Vertical Entertainment |
| 13 | Shiva Baby | $159,294 | 27 | $7,160 | 4.5% | 12 | Apr 2 | - | Utopia |
| 14 | Cliff Walkers | $152,972 | 65 | $53,142 | 34.7% | 65 | Apr 30 | - | CMC Pictures |
| 15 | SAS: Rise of the Black Swan | $146,329 | 189 | $78,721 | 53.8% | 189 | Apr 16 | - | Vertical Entertainment |
| 16 | Held | $142,817 | 129 | $46,277 | 32.4% | 129 | Apr 9 | - | Magnolia Pictures |
| 17 | Gunda | $115,691 | 35 | $5,023 | 4.3% | 5 | Apr 16 | - | Neon |
| 18 | About Endlessness | $51,386 | 17 | $8,809 | 17.1% | 17 | Apr 30 | - | Magnolia Pictures |
| 19 | Monday | $30,932 | 54 | $18,767 | 60.7% | 54 | Apr 16 | - | IFC Films |
| 20 | Trigger Point | $29,262 | 77 | $29,262 | 100% | 77 | Apr 16 | - | Screen Media Films |
| 21 | Jakob's Wife | $27,588 | 101 | $27,588 | 100% | 101 | Apr 16 | - | RLJ Entertainment |
| 22 | Moffie | $24,520 | 51 | $14,007 | 57.1% | 51 | Apr 9 | - | IFC Films |
| 23 | We Broke Up | $15,063 | 35 | $11,003 | 73% | 35 | Apr 16 | - | Vertical Entertainment |
| 24 | Endless Rain | $7,334 | 14 | $2,663 | 36.3% | 14 | Apr 30 | - | Sony Pictures Releasing |
| 25 | Blood Brothers: Civil War | $5,191 | 2 | $1,606 | 30.9% | 2 | Apr 2 | - | Indican Pictures |
| 26 | Bill Traylor: Chasing Ghosts | $4,504 | 2 | $1,666 | 37% | 2 | Apr 16 | - | Kino Lorber |
| 27 | Slalom | $2,788 | 4 | $1,052 | - | 4 | Apr 9 | - | Kino Lorber |
