Round 1 of the 2021 MLB draft took place last night with the Pittsburgh Pirates holding the number 1 overall selection. With rounds 2-10 slated to take place on Monday July 12th, here are the results of the first round, plus the compensation/competitive balance rounds from Sunday:
| Pick | Team | Player | Pos. | School |
| 1 | Pirates | Henry Davis | C | Louisville |
| 2 | Rangers | Jack Leiter | RHP | Vanderbilt |
| 3 | Tigers | Jackson Jobe | RHP | Heritage Hall High (Oklahoma) |
| 4 | Red Sox | Marcelo Mayer | SS | Eastlake High (California) |
| 5 | Orioles | Colton Cowser | OF | Sam Houston |
| 6 | Diamondbacks | Jordan Lawlar | SS | Jesuit Prep (Texas) |
| 7 | Royals | Frank Mozzicato | LHP | East Catholic High (Connecticut) |
| 8 | Rockies | Benny Montgomery | OF | Red Land High (Pennsylvania) |
| 9 | Angels | Sam Bachman | RHP | Miami (Ohio) |
| 10 | Mets | Kumar Rocker | RHP | Vanderbilt |
| 11 | Nationals | Brady House | SS | Winder-Barrow High (Georgia) |
| 12 | Mariners | Harry Ford | C | North Cobb High (Georgia) |
| 13 | Phillies | Andrew Painter | RHP | Calvary Christian High (Florida) |
| 14 | Giants | Will Bednar | RHP | Mississippi State |
| 15 | Brewers | Sal Frelick | OF | Boston College |
| 16 | Marlins | Kahlil Watson | SS | Wake Forest High (North Carolina) |
| 17 | Reds | Matt McLain | SS | UCLA |
| 18 | Cardinals | Michael McGreevy | RHP | UC Santa Barbara |
| 19 | Blue Jays | Gunnar Hoglund | RHP | Mississippi |
| 20 | Yankees | Trey Sweeney | SS | Eastern Illinois |
| 21 | Cubs | Jordan Wicks | LHP | Kansas State |
| 22 | White Sox | Colson Montgomery | 3B | Southridge High (Indiana) |
| 23 | Indians | Gavin Williams | RHP | East Carolina |
| 24 | Braves | Ryan Cusick | RHP | Wake Forest |
| 25 | Athletics | Max Muncy | SS | Thousand Oaks High (California) |
| 26 | Twins | Chase Petty | RHP | Mainland Regional High (New Jersey) |
| 27 | Padres | Jackson Merrill | SS | Severna Park High (Maryland) |
| 28 | Rays | Carson Williams | SS/RHP | Torrey Pines High (California) |
| 29 | Dodgers | Maddux Bruns | LHP | UMS-Wright Prep (Alabama) |
Compensation pick result
| Pick | Team | Player | Pos. | School |
| 30 | Reds | Jay Allen | OF | John Carroll High (Florida) |
Competitive Balance Round A results
| Pick | Team | Player | Pos. | School |
| 31 | Marlins | Joe Mack | C | Williamsville East High (New York) |
| 32 | Tigers | Ty Madden | RHP | Texas |
| 33 | Brewers | Tyler Black | 2B | Wright State |
| 34 | Rays | Cooper Kinney | 2B | The Baylor Schools (Tennessee) |
| 35 | Reds | Matheu Nelson | C | Florida State |
| 36 | Twins | Noah Miller | SS | Ozaukee High (Wisconsin) |