Santo Tomas comprises 19 barangays with an estimated population of 150,679. 14 of its barangays (74%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Balagunan | 5,716 | 6 | Crowdsourced signal only (no registered tower) |
| Bobongon | 11,573 | 0 | Dead zone: no towers from any source |
| Casig-Ang | 2,905 | 0 | Dead zone: no towers from any source |
| Esperanza | 1,366 | 0 | Dead zone: no towers from any source |
| Kimamon | 7,795 | 3 | Crowdsourced signal only (no registered tower) |
| Kinamayan | 13,064 | 0 | Dead zone: no towers from any source |
| La Libertad | 10,727 | 0 | Dead zone: no towers from any source |
| Lungaog | 4,384 | 0 | Dead zone: no towers from any source |
| Magwawa | 1,182 | 0 | Dead zone: no towers from any source |
| New Katipunan | 6,507 | 0 | Dead zone: no towers from any source |
| New Visayas | 7,114 | 0 | Dead zone: no towers from any source |
| Pantaron | 5,535 | 0 | Dead zone: no towers from any source |
| Salvacion | 7,814 | 0 | Dead zone: no towers from any source |
| San Jose | 3,844 | 0 | Dead zone: no towers from any source |
| San Miguel | 3,178 | 5 | Crowdsourced signal only (no registered tower) |
| San Vicente | 3,588 | 0 | Dead zone: no towers from any source |
| Talomo | 6,671 | 1 | Crowdsourced signal only (no registered tower) |
| Tibal-og (Pob.) | 43,642 | 7 | Crowdsourced signal only (no registered tower) |
| Tulalian | 4,074 | 0 | Dead zone: no towers from any source |