Would Aluminum putty be ideal to fill in a tiny hole on aluminum oil pan?

I'd not expect anything out of a can to work. First of all, how are you going to clean the oil off the surface enough so it will even stick, especially if you can't get to the back side?

In reality, I'd try orange RTV before I tried any epoxy/metal filler stuff. Still going to have an adhesion problem as oil can't just be wiped off for bonding (and bonding on both sides of the hole is the only hope to seal this), but it's more likely to work than epox. I'd let it harden for 24 hrs before I put oil back in it though.

You might also be able to get someone to TIG the hole up, but no idea what someone is going to charge for that. Pan replacement may be cheaper. It's definitely the best option.

Edit: Find it funny to get a thumb down, when RTV is used to seal intakes to the engine block, which is of course, exposed to hot engine oil at all times.

Just get a short metal screw at any hardware store that is slightly thicker than the hole. Pick one with a wide head and get a small rubber washer to fit that. That will cost you about 25 cents, needs nothing but a screwdriver and will take you 1 minutes to screw it in. ,,,,,,,,,no need to drain any oil.

Epoxy putty might work but I would always worry it might drop out on a trip and total the engine. It is worth enquiring of welding shops that specialise in aluminium repair. In the UK alloy sumps can be repaired by these guys. See link for example. I am sure there will be similar firms in the US.

Permatex makes a product called " gas tank repair" It is made to plug small rust holes in metal gas tanks. This is the only product I know that is not affected by oil and gas. All epoxies will soften and fall off with exposure to any petroleum product. It is available at any good auto parts store.

I would be inclined to use a pop rivet with an O-ring on it if the hole is not on an edge. After all, any repair is going to be hokey and at least this will be a durable hokey repair.

I did what anonymous did, then after cleaning with brake cleaner spray, plastered over the screw with JB Weld. No leaks after years.

it might patch the hole if all mating surfaces are clear of oil but that alone is tricky.