| Oberg, Karen OTR/L | Aspen Grove Therapy and Wellness Center, LLC | (406) 541-2776 |
| Offerdahl, Daniel CRNA | Butte Clinic - Anesthesia | (406) 723-2472 |
| Ogger, Kelly LCSW | Big Sky Behavioral Health PLLC | (406) 672-8411 |
| Ohl, Theresa FNP-BC | Beartooth Billings Clinic | (406) 446-2345 |
| Ohl, Theresa FNP-BC | Beartooth Billings Clinic - Clinic | (406) 446-2345 |
| Olds, Jenna FNP | Cogent Healthcare of MT dba Sound Physicians | (406) 657-7000 |
| Olds, Jenna FNP | North Shiloh Clinic - Transitional Care Group | (406) 237-8282 |
| Olds, Jenna FNP | SVH Hospitalists | (406) 237-3850 |
| Oley, Erin FNP | Beartooth Billings Clinic | (406) 446-2345 |
| Oley, Erin FNP | Beartooth Billings Clinic - Clinic | (406) 446-2345 |
| Oley, William MD | Beartooth Billings Clinic | (406) 446-2345 |
| Oley, William MD | Beartooth Billings Clinic - Clinic | (406) 446-2345 |
| Oligbo, Molly PMHNP-BC | Beartooth Billings Clinic | (406) 446-2345 |
| Oligbo, Molly PMHNP-BC | Beartooth Billings Clinic - Clinic | (406) 446-2345 |
| Oliver, Cindy LCPC | Yellowstone Boys & Girls Ranch | (406) 656-3112 |
| Oliver, Cindy LCPC | Yellowstone Boys & Girls Ranch - Chemical Dependency | (406) 245-2751 |
| Oliver, Kynzie PA | Billings Dermatology PC - Billings (fka:Tallman Dermatology) | (406) 294-9515 |
| Olson, Catherine OD | Ophthalmic Associates of Billings LLC | (406) 256-6000 |
| Olson, Brittany LCPC, LAC | Yellowstone Boys & Girls Ranch | (406) 656-3112 |
| Olson, Brittany LCPC, LAC | Yellowstone Boys & Girls Ranch - Chemical Dependency | (406) 245-2751 |
| Olson-Meyer, Sharda LCSW | Sentinel Mental Health Inc | (406) 272-2511 |
| Olson-Meyer, Sharda LCSW | Sentinel Mental Health Inc - Helena | (406) 272-2511 |
| Olutola, Olatoye MD | Butte Clinic - General Surgery | (406) 723-2951 |
| Omar, Holly MD | Holy Rosary Healthcare | (406) 233-2600 |
| Omar, Holly MD | Holy Rosary Healthcare Clinic | (406) 233-2500 |
