Most credit unions in Quebec are part of the Desjardins group. They don't seem especially widespread outside of Quebec.

Quickly glancing at the ownership of 9 of the 10 largest credit unions outside of Quebec, 8 of the 9 were unrelated to Desjardins. The 4th largest (Meridian Credit of Ontario) was the sole exception. I couldn't find info on the 9th largest, Cambrian Credit of Manitoba.