One option is an Anderson Power Pole single-pin connector. These are a hermaphrodite 30 Amp single-pin connector that can be ganged together to make a connector that has as many pins as you want.
They are commonly seen in stage-lighting dimmer racks to patch the pins on the multi-pin Socapex connectors to the specific dimmer channel desired.
They are massively reliable and relatively inexpensive.
You can see them here. According to that page, the small ones are good for up to 45 Amps and all are rated for 600 Vac operation. They are UL listed and I know that I've seen them with CSA markings as well.
I really like these connectors - I've been using Power Pole connectors for decades and have always had great results with them. You will often see the larger double-pin connectors used in electric fork lifts for the battery connections.
I just realized that you didn't specify what voltage and current you wanted.
There are large single-pin connectors available that are used for temporary AC power distribution panels. These go by the names "Camlock" & "Tweeco" and are available in current rating up to 200 Amps or more.
Have a chat with your local electricians about those if you need something that large.