| Puccinia oaxacana Dietel & Holw., 1901 |
| Puccinia obesiseptata Cummins, M. P. Britton & J. W. Baxter, 1969 |
| Puccinia obesispora Arthur, 1918 |
| Puccinia obliqua Berk. & M. A. Curtis, 1868 |
| Puccinia obtecta Peck, 1873 |
| Puccinia oenotherae Vize, 1877 |
| Puccinia oncidii Cummins, 1960 |
| Puccinia opaca Dietel & Holw., 1897 |
| Puccinia oxalidis Dietel & Ellis, 1895 |
| Puccinia pallidissima Speg., 1881 |
| Puccinia pampeana Speg., 1880 |
| Puccinia panicicola Arthur, 1907 |
| Puccinia parilis (Arthur) Arthur, 1918 |
| Puccinia parthenices H. S. Jacks., 1922 |
| Puccinia parthenii (Speg.) Arthur, 1910 |
| Puccinia paulensis Rangel, 1918 |
| Puccinia pelargonii-zonalis Doidge, 1926 |
| Puccinia pentstemonis Peck, 1885 |
| Puccinia perasperata J. F. Hennen & Cummins, 1973 |
| Puccinia phlyctopus P. Syd. & Syd., 1902 |