| Name | Labels | City | State / Province |
|---|
| O'Nan's K-9 Academy | facilitytraining | South Henderson | KY |
| OBay Shelties | blogvideo | | |
| OG Bad Soden / Germany | club | Bad Soden | |
| OKPAWS K9 Sports Club | club | Oklahoma City | OK |
| OUTBACKAgility | rental | Fresno | CA |
| OakLines PDF Express Entries | service | | |
| Oakview Training Center | facilitytraining | Wauconda | IL |
| Obedience Plus | training | Hemet | CA |
| Obedience Training Club of Wichita Falls, Inc | clubfacilitytraining | Wichita Falls | TX |
| OceanWolf Agility | facilitytraining | Sarasota | FL |
| On Course Agility - Karen Holik | generalonlinetrainingvideo | | FL |
| On Good Behavior | facilitytraining | Franklin Park | NJ |
| On Target Dog Training | facilitytraining | Colborne | ON |
| One Smart Dog | facilityrentaltraining | Seville | OH |
| One eyed agility supporter and micro friend | blog | | Victoria |
| OneMind Dogs | blogonlinevideo | | |
| Online Dog Coach | equipmentgeneralvideo | Littleton | CO |
| Opportunity Barks Dog Training & Behavior | facilitytraining | Philadelphia, | PA |
| Orchid Isle Dog Agility | clubtraining | Keaau | HI |
| Oregon School for Clever Dogs | onlinetraining | Bend | OR |
| Oshkosh Kennel Club | clubtraining | Oshkosh | WI |
| Ouachita Valley Dog Training Club, Inc. | clubtraining | West Monroe | LA |
| Over the Top Agility Team | clubfacilitytraining | Schertz | TX |
| Over! Rover Agility Equipment | equipment | | |