| | SG | Waived (The Boston Celtics waived G Lonnie Walker IV.) |
| | SF | Waived (The Boston Celtics waived G-F Ron Harper Jr..) |
| | SG | Waived (The Boston Celtics waived G Jay Scrubb.) |
| | SG | Signed/Offer Sheet (The Boston Celtics signed G Jay Scrubb.) |
| | SG | Signed/Offer Sheet (The Boston Celtics signed G Lonnie Walker IV.) |
| | SF | Signed/Offer Sheet (The Boston Celtics signed F signed Anton Watson to a two-way contract.) |
| | PF | Contract Extended (The Boston Celtics signed F Sam Hauser to a contract extension.) |
| | PG | Signed/Offer Sheet (The Boston Celtics signed G JD Davison to a two-way contract.) |
| | PF | Re-Signed (The Boston Celtics re-signed F-C Xavier Tillman Sr.) |
| | SF | Contract Extended (The Boston Celtics signed F-G Jayson Tatum to a contract extension.) |
| | SG | Contract Extended (The Boston Celtics signed G Derrick White to a contract extension.) |
| | PF | Declared Free Agency (F-C Xavier Tillman Sr. elected free agency.) |
| | PG | Declared Free Agency (G JD Davison elected free agency.) |
| | SF | Declared Free Agency (G-F Svi Mykhailiuk elected free agency.) |
| | SF | Declared Free Agency (F-G Oshae Brissett declared free agency.) |