Hello Eli, Look for Tom's of Maine. In the US it is available in almost all health food stores. But, look carefully, Tom's also now makes flouride toothpastes which are sold at many grocery and drug stores.
Is there a particular reason why you are looking for a non-fluoride toothpaste?
Have you tried Amazon.com? I did a search there and found a few brands. I'm not familiar with any of them so I can't really comment on its effectiveness in comparison to fluoridated toothpaste in preventing cavities.