SharePoint hub sites

A hub site in SharePoint Online is a SharePoint site (usually a communication site) that other sites can associate with. Associated sites inherit the hub's top navigation, theme, search scope, and (optionally) news aggregation. It's the modern building block for intranets that aren't all in one giant site.

Why hub sites exist

Before hub sites, large intranets either lived in one enormous site collection with rigid permissions, or sprawled across dozens of independent sites with no shared navigation. Hub sites split the difference: each site keeps its own permissions and lifecycle, but they appear unified to users.

What associating a site to a hub gives you

• Shared top navigation that's edited once on the hub and shows everywhere.
• Shared theme and logo for visual consistency.
• Shared search scope — searching from any associated site searches across the whole hub.
• Rolled-up news and content in hub web parts.
• Common nav and chrome without copying anything between sites.

A site is associated to exactly one hub at a time, but the hub itself can be associated with a parent hub — creating two levels of nesting. Microsoft also added hub-to-hub associations for very large intranets.

Anatomy of a modern intranet

A typical structure:

• A company home hub (communication site).
• Department hubs (HR, Finance, Engineering, Sales) — each a communication site, each a hub.
• Project, team, and unit team sites associated to the relevant department hub.
• Microsoft 365 Group sites and Teams sites also associated, if appropriate.

Users see one coherent intranet; admins manage each site separately.

Limits and practical notes

• A tenant supports up to 2,000 hub sites, though most organisations have far fewer.
• Designating a site as a hub requires the SharePoint admin role and is done in the SharePoint admin center.
• Hub navigation is text + links — it's not a full content management system, so keep it small and well-structured.
• Tenant-wide navigation policies can also enforce home-site behaviour on top of hubs, since SharePoint introduced home site and Viva Connections as the entry-point experience.

Used carefully, hub sites give a federated intranet a coherent feel without forcing everyone into a single permissions model.

Hub sites, home sites, and Viva Connections

These three names get confused; they solve different problems:

• Hub site — a shared navigation, theme, and search scope for a group of associated sites. Zero to many per tenant.
• Home site — the one site tenant-designated as the intranet landing page (SPO PowerShell: Set-SPOHomeSite). It is usually also a hub. There is exactly one per tenant. It unlocks tenant-wide search, the global navigation bar, and the entry point for Viva Connections.
• Viva Connections — the Teams-embedded dashboard, feed, and resources experience that reads from the home site and the global navigation.

The order to think about it: build hubs where they make sense, promote one of them to the home site, layer Viva Connections on top.

Rollout patterns that work

The intranets that stay tidy tend to use one of three shapes:

• One hub per business function. Company home hub, plus HR, Finance, IT, Sales, Marketing, Engineering hubs. Team sites and project sites associate to whichever department owns them. Simplest to explain to owners.
• One hub per audience. All-employee hub, People-managers hub, Field-workers hub. Content is organised around who reads it rather than who owns it. Requires stronger central editorial to avoid duplicating pages across audience hubs.
• Regional plus functional. Global company hub, regional hubs (Nordics, DACH, APAC), functional hubs cross-cutting them. Only worth the extra complexity for genuinely multi-regional organisations with local content ownership.

Two levels of hub nesting are supported and hub-to-hub associations extend that, but keep it shallow. Deeply nested hub trees confuse users and dilute the shared-navigation benefit.

Common wrong turns

• One hub per team. Hubs are for federations of sites, not for individual team sites. A hub with one associated site adds admin surface for no user value.
• Rebuilding navigation to match Active Directory. Users search for topics, not org charts. Reorg-driven hub re-wiring becomes a permanent tax.
• Hub navigation as a full CMS. The nav is a small list of links; it is not the place for landing content. Put content on pages, link to the pages from the nav.
• Skipping search scope planning. Associating a site to a hub joins it to that hub's search scope. If two hubs share sensitive content owners, understand who now sees what in Search everything.
• Turning off site-level branding to keep the hub's theme consistent. Hub theme is inherited; site owners can still override colours and logos. Decide up front whether that is a policy the intranet team enforces or a freedom site owners keep.

Limits worth remembering

• 2,000 hub sites per tenant. Practical hub counts are usually low double digits.
• Hub join is a SharePoint admin operation for a site not owned by the requester; site owners can request association via the site's Site Information panel and an admin approves.
• Search results roll up from associated sites but respect permissions — a user only sees what they can already access.
• Theming applies to modern pages and chrome; classic pages still render with their own themes and are a good reason to modernise before restructuring.
• Hub association is reversible. Unlinking removes the shared nav and theme but leaves content and permissions intact.