| Business | Phone |
| Code Enforcement 28 Nassau Ave, Islip 11751 | (631) 224-5473 |
| Islip Board Of Appeals 1 Manitton Ct, Islip 11751 | (631) 224-5489 |
| Islip Building Div 1 Manitton Ct, Islip 11751 | (631) 224-5469 |
| Islip Code Enforcement 24 Nassau Ave, Islip 11751 | (631) 224-5548 |
| Islip Drug & Alcohol Counseling 401 Main St, Islip 11751 | (631) 224-5330 |
| Islip Engineering 1 Manitton Ct, Islip 11751 | (631) 224-5360 |
| Islip Engineering 401 Main St, Islip 11751 | (631) 224-5360 |
| Islip Grange Broadway Ave & Mainamp;, Islip 11751 | (631) 472-7016 |
| Islip Human Development 401 Main St # 106, Islip 11751 | (631) 224-5325 |
| Islip Industrial Dev Agency 40 Nassau Ave, Islip 11751 | (631) 224-5532 |
| Islip Personnel Office 655 Main St, Islip 11751 | (631) 224-5520 |
| Islip Purchasing 40 Nassau Ave, Islip 11751 | (631) 224-5515 |
| Islip Receiver Of Taxes 40 Nassau Ave # 4, Islip 11751 | (631) 224-5580 |
| Islip Resource Recovery Agency 401 Main St, Islip 11751 | (631) 224-5644 |
| Islip Rifle & Pistol Range Freeman Ave, Islip 11751 | (631) 224-5479 |
| Islip Senior Citizens 401 Main St, Islip 11751 | (631) 224-5340 |
| Islip Supervisor's Office 655 Main St, Islip 11751 | (631) 224-5500 |
| Islip Town Board Office 655 Main St, Islip 11751 | (631) 224-5560 |
| Islip Youth Bureau 401 Main St, Islip 11751 | (631) 224-5320 |