| Business | Phone |
| Nassau County 4-H Club Farm 3186 Sound Ave, Riverhead 11901 | (631) 727-0391 |
| Riverhead Building Dept 210 Howell Ave, Riverhead 11901 | (631) 727-3200 |
| Riverhead Community Awareness 540 E Main St, Riverhead 11901 | (631) 727-3722 |
| Riverhead Historian 542 E Main St, Riverhead 11901 | (631) 369-9717 |
| Riverhead Municipal Garage 1412 Route 58, Riverhead 11901 | (631) 369-2391 |
| Riverhead Sewer Dist Operation Riverside Dr, Riverhead 11901 | (631) 727-3200 |
| Riverhead Street Lighting Youngs Ave, Riverhead 11901 | (631) 727-2971 |
| Riverhead Superintendent-Hwys 56 Osborne Ave, Riverhead 11901 | (631) 727-3200 |
| Riverhead Town Office 747 E Main St, Riverhead 11901 | (631) 369-6925 |
| Town Of Riverhead Scavenger River Ave, Riverhead 11901 | (631) 727-6265 |