Oeiras's 2026 population is now estimated at 181,965. In 2021, the population of Oeiras was 171,836. Oeiras has grown by 2,061 in the last year, which represents a 1.15% annual change. These population values and projections come from Portugal INE API indicator 0012917 resident population municipal total and World Population Review Internal Projections .
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| Lisbon | 596,952 | 1.83% |
| Sintra | 410,420 | 1.17% |
| Vila Nova de Gaia | 317,859 | 0.78% |
| Porto | 264,493 | 2.31% |
| Cascais | 228,079 | 1.28% |
| Loures | 214,856 | 1.18% |
| Braga | 209,328 | 1.42% |
| Amadora | 187,541 | 1.62% |
| Almada | 187,519 | 1.05% |
| Matosinhos | 185,501 | 1.22% |
| Seixal | 183,000 | 1.71% |
| Oeiras | 181,965 | 1.15% |
| Gondomar | 171,928 | 0.75% |
| Odivelas | 161,278 | 1.59% |
| Guimaraes | 156,587 | 0.02% |
| Coimbra | 150,409 | 1.19% |
| Maia | 149,556 | 1.68% |
| Santa Maria da Feira | 142,787 | 0.79% |
| Vila Franca de Xira | 142,764 | 0.73% |
| Leiria | 140,182 | 1.52% |
