| NISD | Nacogdoches Independent School District 
| Others |
| NISD | National Institute for Scuba Diving
| Others |
| NISD | National Institute of Scuba Diving
| Others |
| NISD | National Institute of Social Defence
| Others |
| NISD | National Institute of Social Defense
| Others |
| NISD | National Institute of Steel Detailing
| Others |
| NISD | Natural Interactive Services Division
| Others |
| NISD | Navarro Independent School District
| Others |
| NISD | Navasota Independent School District
| Others |
| NISD | Nederland Independent School District
| Others |
| NISD | Needville Independent School District
| Others |
| NISD | Northside Independent School District
| Others |
| NISD | Northwest Independent School District
| Others |