| 2018 Section XI Overall Championship Bracket | ||||||
| Tuesday | Saturday | Monday | Friday | |||
| February 20, 2018 | February 24, 2018 | February 26, 2018 | March 2, 2018 | |||
| Greenport (20-2) | Amityville (22-1) | |||||
| C Champion | A Champion | |||||
| 67-41 | Greenport (21-2) | 75-60 | Amityville (23-1) | |||
| @ SCCC-Selden | C/D Champion | @ William Floyd HS | A/B/C/D Champion | |||
| Bridgehampton (8-10) | 72-81 | Center Moriches (20-2) | 77-69 | Amityville (24-1) | ||
| D Champion | @ Sachem North HS | B/C/D Champion | @ SUNY Farmingdale | Section XI Champion | ||
| Center Moriches (19-2) | HH Hills East (21-2) | |||||
| B Champion | AA Champion | |||||