Main UST Trunklines: 406-1611
| Office | Local | Direct |
| Academic Affairs | 8231/8415 | 731-3038 |
| Accounting Division | 8215 | 740-9706 |
| Architecture | 8229 | 740-9721 |
| Arts and Letters | 8220 | 731-4003 |
| Beato Angelico | 8344 | |
| Campus Ministry | 8321 | 740-9719 |
| Cashier's Office | 8217 | 731-4322 |
| Center for Educational Research & Development | 4038 | 314-0852 |
| Center for Intercultural Studies | 8340 | 740-9716 |
| Central Library | 8234 | 731-3034 |
| Central Seminary | 711-7732 | |
| Central Student Council | 8322 | |
| Civil Law | 8225 | 731-4027 |
| Commerce | 8272/8258 | 731-3124 |
| Community Development | 8420 | 742-3707 |
| DMST/ROTC | 8312 | |
| Ecclesiastical Faculties | 8261 | 731-4066 |
| Education | 8260/8392 | 731-4323 |
| Education High School | 8237 | 731-2952 |
| Educational Technology Center | 8332/8339 | 740-9701 |
| Elementary | 8248 | 731-5722 |
| Engineering | 8275 | 731-4041 |
| External Affairs/ Grants Office | 8430 | 749-9730 |
| Fine Arts and Design | 8390 | 740-9703 |
| Foreign Students Office | 8329 | 740-9717 |
| Graduate School | 8247 | 731-5396 |
| Guidance and Counseling Office | 8212 | 740-9720 |
| Health Service | 8211 | 731-4311 |
| High School | 8270 | 731-4785 |
| Hospital | 731-3001 | |
| Human Resource Department | 8254 | 731-3533 |
| ID Room | 8233 | |
| Institute of PE & Athletics | 8227 | 731-5744 |
| Institute of Technological Courses | 8320 | |
| Laboratory Equipment and Supplies Office | 8266 | 712-6349/ 731-3001 |
| Legal Aid Clinic | 8349 | 732-3045 |
| Medicine and Surgery | 8239 | 741-5314 |
| Museum of Arts and Sciences | 8337/8269 | 781-1815 |
| Music | 8246 | 731-4022 |
| Nursing | 8241 | 731-5738 |
| Pharmacy | 8223 | 731-4040 |
| Planning and Development | 8413 | 740-9731 |
| Post Office | 8284 | |
| Public and Alumni Affairs Office | 8315 | 731-3544 |
| Publishing House | 8252/8278 | 731-3522 |
| Rector's Office | 8210 | 731-3123 |
| Registrar's Office | 8279 | 731-5709 |
| Rehabilitation Sciences | 8280 | 740-9713 |
| Religion | 8256 | 731-4301 |
| Santisimo Rosario Parish | 731-3062 | |
| Santo Tomas E-services ProviderS (STEPS) | 8311 | 731-6933 |
| Science | 8224 | 731-5728 |
| Secretary General | 8219/8421 | 731-3119 |
| Security Office | 8318 | |
| Student Accounts Section | 8288 | |
| Student Admissions | 8276 | 309-7211 to 13 |
| Student Affairs | 8267/8294 | 731-2985 |
| The Varsitarian | 8235 | |
| Treasurer's Office | 8218 | 740-9726 |
| Vice-Rector's Office | 8262 | 731-0553 |