1. Oat Hills - Colusa County
2. Oat Hills - Mariposa County
3. Oat Hills - San Diego County
4. Oat Hills - Yuba County
5. Ogilby Hills - Imperial County (Cibola National Wildlife Refuge)
6. Old Dad Mountains - San Bernardino County
7. Old Woman Mountains - Mojave Desert (south of Essex)
8. Ord Mountains - Mojave Desert (SE of Barstow)
9. Orocopia Mountains - Riverside County (east of Coachella Valley)
10. Owlshead Mountains - south Death Valley NP

1. Palen Mountains - Riverside County (NE of Chuckwalla Mountains)
2. Palisades - Napa County
3. Palo Verde Mountains - Imperial County (westside of Colorado River)
4. Palos Verdes Hills - coastal Los Angeles (landed end of the Channel Islands)
5. Panamint Mountains - western side of Death Valley
6. Panhandle Hills - Siskiyou County
7. Panoche Hills - Fresno County (east of Diablo Range)
8. Panorama Hills - southeastern Carrizo Plain National Monument
9. Paradise Range - San Bernardino County
10. Partlett Mountains - San Bernardino County
11. Pedley Hills - NW Riverside County (Jurupa Valley city)
12. Peralta Hills - Orange County (toward Olive)
13. Pine Hills - San Diego County
14. Pinto Mountains - Joshua Tree NP
15. Pinyon Mountains - Anza Borrego Desert State Park
16. Piute Range - eastern Mojave National Preserve
17. Pleito Hills - SW Kern County
18. Point of Rocks - San Bernardino County (unnamed mountains near Helendale)
19. Potrero Hills (Ridge) - Richmond 20. Poverty Hills - Inyo County (NW of Bishop)
21. Providence Mountains - Mojave Desert (Mitchell Caverns)
22. Puente Hills - near Hacienda Heights (SR-60 Pomona Fwy)
23. Pyramid Mountains - Kings County

1. Quail Mountains - SW of Death Valley NP