A few days ago, one of my patrons asked me who owns jinja, and while I gave them a short answer then, I promised a longer answer on the blog, because I thought it would probably be more broadly interesting, This is that answer.
It depends on the jinja.
OK, OK, so that’s the answer to any question about Shinto. It is possible to be a lot more informative in this case, because almost all jinja are in Japan, and thus have to follow Japanese law when it comes to questions of ownership. There are basically three possibilities.
The first is that the land, the buildings, and all the other property are owned by a religious corporation — a shūkyōhōjin. In this case, there are a number of legal requirements for the management of assets, most notably that the corporation has to have a head and a number of other officers, and it must have a site at which a religion is practised. In return, there are tax breaks, and because the corporation is undying, no issues with inheritance tax. There are problems with finding a new priest to serve as the head of the jinja, and with making sure that all such jinja are following all the rules. However, this is clearly the best option for a “standard” jinja, and thus almost certainly the situation for any jinja that you have heard of.
We could say that the jinja owns itself in this case, but things are a little more complex than that. A famous, and extreme, example is Isë Jingū, which is a religious corporation that owns 125 jinja, including both the Inner and Outer Sanctuary, and 123 other jinja scattered around the area, some several kilometres from the central ones. They are all separate jinja, with their own kami, and the matsuri are performed separately at them, but they are all regarded as part of the same religious institution. In some sense, they are all subordinate to the main jinja — Kōtai Jingū, the Inner Sanctuary.
However, this is not always the case. A clear example is Shiwahiko Jinja & Shiogama Jinja in Shiogama, Miyagi Prefecture. In this case, there are two ancient jinja, Shiwahiko Jinja and Shiogama Jinja, which are very close together and both owned by the same religious corporation, which, in Japanese, is just “Shiwahiko Jinja Shiogama Jinja”. Shiogama Jinja is the primary jinja in practice, because Shiwahiko Jinja was moved to be near it about 150 years ago (the previous site was right on the coast, and, if I recall correctly, was on a narrow and eroding strip of land right up against a cliff), and because Shiogama Jinja was the Ichinomiya (primary jinja) for the ancient province. However, Shiwahiko Jinja was also a very important, and ancient, jinja, and so they are equal in theory — but they are still owned by a single religious corporation. Just to complicate things further, Shiogama Jinja consists of two sanctuaries, one of which is split in two to enshrine the kami of Kashima Jingū and Katori Jingū. However, those two (or three, depending on how you count) sanctuaries are part of the same jinja.
And then there are subsidiary jinja. Almost all jinja have subsidiary jinja in the precincts, and these jinja are also owned by the religious corporation that owns the site. They are separate jinja, with their own kami and matsuri. In a few cases, the matsuri for the subsidiary jinja are more important than those for the main jinja, and in more cases there are separate traditions of veneration for different jinja in the grounds. Some subsidiary jinja are on separate sites, sometimes several kilometres away, and these normally have separate traditions of veneration. (Apart from anything else, if they did not they would almost certainly be moved to the grounds.)
Jinja Honchō is also a religious corporation, but it does not own any jinja. Most religious corporations that operate jinja are affiliated with it, although there are exceptions, and the affiliation rules mean that Jinja Honchō must approve new chief priests and certain sorts of change in the property, like selling parts of the precincts. However, a jinja can disaffiliate at any time, and the legal authority does not extend to religious practice, because Japanese law stays out of that question.
Incidentally, the number of jinja in Japan that is often quoted — about 80,000 — is the number of Shinto religious corporations. If you count subsidiary jinja as jinja, then I would guess that the number doubles, at least. Jingū is only one corporation, despite having 125 jinja. My unsystematic experience of jinja suggests that “four” is a possible average number of subsidiary jinja per religious corporation, in which case, with the main jinja, we would be looking at 400,000 actual jinja.
The most important possibility, then, is that a jinja is owned by a religious corporation. The other main possibilities are that a jinja is owned by another type of corporation, and that it is owned by an individual. This normally applies to private sanctuaries, such as a small jinja for the kami of a house, or the jinja for the patron kami of a business or school.
These are arguably not jinja, because they are not always open to the public, but you can also make the case the other way, as they are sites where kami are enshrined and venerated. In most ways, a privately owned jinja is like any other asset. However, Japanese inheritance tax has an exception for ritual sites, which means that a private jinja may be exempt from inheritance tax, if it meets the necessary conditions.
There are also some jinja outside Japan, but I have absolutely no idea how their ownership works.
I wonder how old this structure is. In England, since a long time back, religious sites were indeed organized as some kind of corporation. Blackstone discusses this in his commentaries on the laws of England, published in the 1700s, and from his discussion it is evident this structure was very old even at that time. The English corporation does trace back its structure to the Roman corporation, which is probably also the root of the civil law (continental European) corporation, and probably also of the modern Japanese corporation (the modern Japanese legal system is the result, in part, of the Meiji era adaptation of the Prussian legal system, a civil law system).
It may be that there was some equivalent of a corporation in the pre-Meiji legal system; but even if there was, it may not have been used for shrines. I guess there was a period of time when shrines were frequently under the administration of temples, but this leaves open the question of how temple ownership worked.
This structure is post-war, for jinja. The Meiji government took virtually all jinja, and their lands, into state ownership. Some of that land was returned post-war, when the jinja became religious corporations, but not all of it. My understanding is that the pre-war system for temples and churches was extended to jinja, so yes, this structure probably traces back to the Roman Empire.
My knowledge of pre-Meiji Japanese real estate law is… non-existent. I have no idea what the situation was then. Priests did petition the court to recover lands they claimed had been seized by others, but I do not know what the legal basis was.