Toronto-centric reply:
I use a gas station on Kipling just north of Rexdale which services a lot of propane taxi cabs. There are at least two up there that do it. 

There’s another on Kingston Rd just south of the 401 that I’ve used as well. 

RV campgrounds like KOA are also good candidates. 

Regards, Peter
<< sent from my mobile >>

> On Jul 18, 2019, at 8:37 PM, Andrew Berg <andrew@bergweb.ca> wrote:
> 
> Where does everyone in Southern Ontario get their tanks filled? Have never refilled mine. Can you take it to any fill station like a canadian tire gas bar?
> 
> Andrew