| Pheidole obscurior Forel, 1886 |
| Pheidole obturaculum Longino, 2019 |
| Pheidole obtusospinosa Pergande, 1896 |
| Pheidole opaca Mayr, 1862 |
| Pheidole opaca subsp. apterostigmoides Weber, 1943 |
| Pheidole opaca subsp. sarrita Forel, 1908 |
| Pheidole opaca var. incrustata Forel, 1908 |
| Pheidole optiva Forel, 1901 |
| Pheidole oregonica Emery, 1895 |
| Pheidole pacifica Wheeler, 1915 |
| Pheidole pallidula (Nylander, 1849) |
| Pheidole partita Mayr, 1887 |
| Pheidole pennsylvanica Roger, 1863 |
| Pheidole perdiligens Wilson, 2003 |
| Pheidole perissothrix Longino, 2019 |
| Pheidole perniciosa (Gerstäcker, 1859) |
| Pheidole perpusilla Emery, 1894 |
| Pheidole petrensis Wilson, 2003 |
| Pheidole phanigaster Longino, 2009 |
| Pheidole picata Forel, 1891 |