Nearest PETsMART to St. Marys, Ohio:
Huber Heights, OH
8281 Old Troy Pike
937-236-1335

Nearest PETCO to St. Marys, Ohio:
6655 Sawmill Road
Dublin, OH 43017
614-764-6911

To get step-by-step directions from your house you can use
http://www.maps.yahoo.com OR http://www.mapquest.com