Ownership on an intranet means several things at once, and they sit at different levels. There are rights on a site, accountability for the site itself, and accountability for a page once it is published. Those three often belong to different people, and asking who owns a site gets you whichever of them the person answering has in mind.
Every SharePoint site has a permission group called Site Owners, and the people in it can change how the site works, from permissions and sharing through to navigation. Membership of that group is a set of rights. It is usually set when the site is created and added to later when somebody's existing rights are not enough for what they need to do.
The site owner in the governance sense is the person answerable for the site: whether it should exist, whether what it holds is right, and whether it gets retired. Sometimes that person sits in the Site Owners group. Yet sometimes the group holds nobody but the person who set the site up, who may well have been from IT and moved on to the next request.
Those two meanings come apart more often than they line up, and the gap between them runs through the rest of this post. Everything SharePoint offers uses the permission group, because the group is what SharePoint records and the accountability is not. A site can satisfy every native check on its ownership while nobody is answerable for what it holds.

A content owner, the person answerable for a particular page being accurate, is a third thing again, and SharePoint has no concept of this. Page ownership after publication is the subject of governing the content lifecycle.
Administering the platform is a separate job from owning a site. A site owner can control who gets into their site, though on many intranets access is set above the site and the intranet is open to all staff. A SharePoint administrator holds the tenant-wide settings, and with the SharePoint Advanced Management (SAM) license more governance capabilities are also included for that role.
How many people belong in the Site Owners group
A site with one person in the Site Owners group has nobody once that person moves on, so a minimum of two is the usual answer and the number is yours to set. Our view is that the second name only helps if it belongs to somebody who would notice the site going wrong.
As part of SharePoint Advanced Management, site ownership policies in the SharePoint admin center under Site lifecycle management let you set a minimum owner or admin count and notify the sites that fall below it.
A policy like that works on the Site Owners group and the site admins, so what it measures is membership rather than accountability. A site that clears the policy has enough people holding rights on it. Whether any of them would answer for the site is the separate question, and no native report settles it.
Confirming that owners still recognize their sites
Deciding that every site gets confirmed by its owner on a regular cycle is a governance decision, and it is one of the more useful ones available on an intranet that has grown over time. A site attestation policy is one way to carry it out. Attestation policies ask site owners or admins to confirm on a schedule that a site is still needed and that its owners, members, permissions and sharing settings are right.
The policy is included in the SharePoint Advanced Management capabilities. Where those are not available, the same cycle can run as a manual exercise or through a workflow of your own. What decides whether the cycle works is who confirms and how often, rather than which of those you use to run it.
Confirming ownership on a cycle tells you an owner answered. It doesn't tell you whether anybody noticed a page going wrong in between. Page Authors, one of our apps, displays who last edited a page and when, directly on the page itself, so a second owner or a reader can see at a glance whether anybody has touched it recently. It's a display of activity rather than a register of accountability, and it won't tell you who should have made a change, only who did.
Who can create sites
Self-service site creation and creation by request both work, and two things play a large part in deciding which suits your intranet. The first is how quickly a request gets answered, because a route that takes a week gets bypassed. The second is whether anybody does the naming and ownership work at the point of creation, since a site created without a real owner is creating a problem for later.
External sharing and who approves it
External sharing is a tenant-wide setting and usually sits with IT, because IT carries the consequences of it across the rest of the tenant. What the intranet side owns is narrower and more practical: who can say yes when a team asks to share a library with an agency, and where that answer gets written down so the next team gets the same answer.
Seeing who has access
The data access governance reports in the SharePoint admin center are another tool that comes with SAM, and in part with an E5 license. The set includes snapshot reports on site permissions across the organization and on the sites one user can reach, and activity reports on sharing links and on content shared with everyone except external users, meaning everybody inside your organization. Those activity reports cover the last 28 days.
Site access reviews, also part of SAM, send one of those reports to the site owner to review. Handing the review to the site owner only produces a useful answer where that person knows why the access was granted in the first place, which is the practical argument for the Site Owners group holding a real owner rather than whoever built the site.
Where the mechanics stop short
Every policy described here notifies and nudges, and none of them resolves anything on their own. An ownership policy tells you a site is short of owners, and the site is still short the next morning, until somebody chases the team and finds a name. Setting the minimum is governance and the chasing is management.
The wider gap is that SharePoint records a permission group for a site and holds nothing at all for a page. A site with two attentive owners can carry a hundred pages nobody has read since they went live, and no report in the SharePoint admin center will name anybody for them.
Common questions
How many owners should a SharePoint site have?
More than one, because a single owner means the site has nobody once that person moves on. A site ownership policy, part of SharePoint Advanced Management, lets you set a minimum owner or admin count in the SharePoint admin center and notifies the sites that fall below it. What the policy counts is the Site Owners group and the site admins, so a site passing it is not necessarily the same as a site somebody answers for.
Should an intranet site be open to everyone in the organization?
Usually yes for a site that publishes to the whole organization, and the point is that open access should be something somebody decided rather than something nobody looked at. To confirm where that has happened, the report on content shared with everyone except external users in the SharePoint admin center shows where content has been opened up to everybody inside your organization. Reaching that report needs an E5 license or SharePoint Advanced Management.
What is a site attestation policy in SharePoint?
It asks site owners or admins to confirm on a schedule that a site is still needed and that its owners, members, permissions and sharing settings are correct. The policy is part of SharePoint Advanced Management, and where that is not available the same cycle can be run manually or through a workflow of your own. Who confirms and how often matters more than which of those runs it.
Series links
→ Next in the series: publishing standards for intranet content