| Business | Phone |
| College-Law At La Verne Libr 320 E D St, Ontario 91764 | (909) 460-2070 |
| Oclc Western Svc Center 3281 E Guasti Rd # 560, Ontario 91761 | (909) 937-3300 |
| Ontario Public Library 120 E D St, Ontario 91764 | (909) 395-2004 |
| South Ontario Library 3850 E Riverside Dr, Ontario 91761 | (909) 395-2014 |