| Herndon to Parma Heights (Ohio) | 285.01 mi (458.69 km) |
| Herndon to Parole (Maryland) | 44.86 mi (72.19 km) |
| Herndon to Parsippany (New Jersey) | 204.82 mi (329.63 km) |
| Herndon to Pasadena (California) | 2,266.80 mi (3,648.07 km) |
| Herndon to Pasadena (Maryland) | 46.49 mi (74.81 km) |
| Herndon to Pasadena (Texas) | 1,197.31 mi (1,926.88 km) |
| Herndon to Pasadena Hills (Florida) | 788.71 mi (1,269.30 km) |
| Herndon to Pascagoula (Mississippi) | 868.08 mi (1,397.04 km) |
| Herndon to Pasco (Washington) | 2,155.06 mi (3,468.24 km) |
| Herndon to Passaic (New Jersey) | 216.37 mi (348.22 km) |
| Herndon to Pataskala (Ohio) | 293.05 mi (471.62 km) |
| Herndon to Patchogue (New York) | 262.63 mi (422.66 km) |
| Herndon to Paterson (New Jersey) | 217.30 mi (349.70 km) |
| Herndon to Patterson (California) | 2,354.89 mi (3,789.83 km) |
| Herndon to Pawtucket (Rhode Island) | 374.41 mi (602.55 km) |
