| month | day | visitor | score | home | score |
|---|
| November | 2, 2018 | Celtics | | Knicks | |
| November | 5, 2018 | 76ers | | Celtics | |
| November | 6, 2018 | Celtics | | Raptors | |
| November | 7, 2018 | Celtics | | Heat | |
| November | 10, 2018 | Celtics | | Nets | |
| November | 13, 2018 | Grizzlies | | Celtics | |
| November | 14, 2018 | Raptors | | Celtics | |
| November | 18, 2018 | Rockets | | Celtics | |
| November | 22, 2018 | Kings | | Celtics | |
| November | 23, 2018 | Celtics | | 76ers | |
| November | 24, 2018 | Raptors | | Celtics | |
| November | 25, 2018 | Bulls | | Celtics | |
| November | 26, 2018 | Grizzlies | | Celtics | |
| November | 28, 2018 | Mavericks | | Celtics | |
| November | 29, 2018 | Bucks | | Celtics | |
| November | 30, 2018 | Celtics | | Nets | |
| December | 1, 2018 | Nets | | Celtics | |
| December | 8, 2018 | Celtics | | Pelicans | |
| December | 9, 2018 | Jazz | | Celtics | |
| December | 12, 2018 | Suns | | Celtics | |
| December | 13, 2018 | Nuggets | | Celtics | |
| December | 15, 2018 | Spurs | | Celtics | |
| December | 17, 2018 | Celtics | | Bulls | |
| December | 24, 2018 | Pelicans | | Celtics | |
| December | 26, 2018 | 76ers | | Celtics | |
| December | 28, 2018 | Knicks | | Celtics | |
| December | 31, 2018 | Lakers | | Celtics | |
| January | 1, 2019 | Grizzlies | | Celtics | |
| January | 2, 2019 | Celtics | | Grizzlies | |
| January | 4, 2019 | Wolves | | Celtics | |
| January | 5, 2019 | Pelicans | | Celtics | |
| January | 6, 2019 | 76ers | | Celtics | |
| January | 8, 2019 | Knicks | | Celtics | |
| January | 10, 2019 | Celtics | | Heat | |
| January | 22, 2019 | Celtics | | 76ers | |
| January | 24, 2019 | Celtics | | Hawks | |
| January | 27, 2019 | Celtics | | Sonics | |
| January | 28, 2019 | Celtics | | Pacers | |
| January | 30, 2019 | Celtics | | Wolves | |
| January | 31, 2019 | Celtics | | Hawks | |
| February | 2, 2019 | Heat | | Celtics | |
| February | 13, 2019 | Celtics | | Pelicans | |
| February | 17, 2019 | Celtics | | Warriors | |
| February | 19, 2019 | Celtics | | Raptors | |
| February | 21, 2019 | Celtics | | Jazz | |
| February | 22, 2019 | Nets | | Celtics | |
| February | 23, 2019 | Celtics | | Blazers | |
| February | 24, 2019 | Celtics | | Pelicans | |
| February | 25, 2019 | Celtics | | Lakers | |
| February | 26, 2019 | Clippers | | Celtics | |
| March | 1, 2019 | Bulls | | Celtics | |
| March | 2, 2019 | Hawks | | Celtics | |
| March | 3, 2019 | Warriors | | Celtics | |
| March | 4, 2019 | Celtics | | Knicks | |
| March | 7, 2019 | 76ers | | Celtics | |
| March | 9, 2019 | Celtics | | Bulls | |
| March | 10, 2019 | Bulls | | Celtics | |
| March | 12, 2019 | Bucks | | Celtics | |
| March | 16, 2019 | Pacers | | Celtics | |
| March | 17, 2019 | Celtics | | Knicks | |
| March | 18, 2019 | Celtics | | Knicks | |
| March | 19, 2019 | Heat | | Celtics | |
| March | 20, 2019 | Nets | | Celtics | |
| March | 21, 2019 | Celtics | | Spurs | |
| March | 22, 2019 | Celtics | | Nuggets | |
| March | 23, 2019 | Celtics | | Suns | |
| March | 25, 2019 | Celtics | | Pacers | |
| March | 26, 2019 | Pelicans | | Celtics | |
| March | 28, 2019 | Hawks | | Celtics | |
| March | 29, 2019 | Celtics | | Kings | |
| March | 30, 2019 | Celtics | | Bucks | |
| April | 6, 2019 | Sonics | | Celtics | |
| April | 7, 2019 | Celtics | | Clippers | |
| April | 10, 2019 | Celtics | | Heat | |
| April | 14, 2019 | Blazers | | Celtics | |
| April | 15, 2019 | Celtics | | Bucks | |
| April | 16, 2019 | Pacers | | Celtics | |
| April | 18, 2019 | Celtics | | Heat | |
| April | 20, 2019 | Celtics | | Nets | |
| April | 24, 2019 | Celtics | | Mavericks | |
| April | 25, 2019 | Celtics | | Grizzlies | |
| April | 26, 2019 | Celtics | | Rockets | |