Can civilians own military aircraft?

Can civilians fly military aircraft?

I am not sure if you are asking about such a plane (rent one for example) or one have . But either way the answer is yes.

I flew a Hawker Hunter at a (now defunct) location in Cape Town on a mixed low-level / acrobatic flight down the coast. There were no restrictions on who could fly on the plane other than the obvious (no children; must be of reasonable height / weight and general fitness), but they did not allow non-pilots to take control. We did aerobatics (up to 5G, from memory) and I had the controls in the cruise flight for about 10 minutes. There was absolutely nothing a civilian couldn't learn: it's "just" another airplane.

As for owning one, this is not at all unusual. Privately owned ex-military aircraft are often referred to as "warbirds," and the US even has an EAA ownership organization. The aircraft are usually viewed as experimental (or local equivalent) for regulation and airworthiness purposes.

The barriers to owning these planes (as always) are money and education. It is very expensive to buy and maintain because there are so few parts or mechanics available and insurance is (almost) impossible, so most owners will have to self-insure. Operating costs are also typically high, especially when the aircraft systems require "exotic" fuels, gases, lubricants, or other consumables. For ejector seats, you may need to include explosives on the list.

Training is a similar problem as so few people can instruct you on how to fly a military aircraft, but this is obviously not a total barrier, and I expect you will find it if you get involved in this part of the flying community that Contacts you need.

So if you can legally buy a military aircraft in your country, if you have enough money to operate and maintain, if you can find someone to train you, and if you can meet your local regulations for non-type (experimental) aircraft then you can You absolutely do it. But for most people that's a lot of ifs :-)