You can do that on the Global Page, and make the region conditional (display only on the pages where you need them).

Thanks inol, Of course, I know about page 0, but,  I think the page 0 solution would definitely not scale.  not to mention would add potentially unneeded overhead.

I think this is a great idea. I have been working with Apex for years and it would be very interesting to have this possibility. As maahelal says, it can be implemented as a shared component. 

I would add that this shared component could accept arguments, as if it were a function or procedure in a programming language. These arguments would be tied to page items when the shared region is inserted into a page. For example, a "shared" interactive report could be embedded in different pages, each one filtering the result based on the value of a page element on that page.

I think that this is a great idea. Indeed this could be achieved by having “Page subscriptions” and “Region subscriptions” like whe have for templates and themes. This way we could have global page and region funcionality across applications, change in one place, and replicate it with just a click.

Yes, this would be fantastic.

The decision to use such regions is made during development, not at runtime. So there is no need to clutter up page zero with a bunch of regions conditioned by page number. Reusable regions could be stored as a new type of shared component. Page items would be created in the usual way but with neutral page-number-names, which would be populated when the region is selected for inclusion on a page, by virtue of a placeholder reference which also serves to indicate the location of the region on any page which invokes it.

Developers would see the region on the page they are working on, but it would be protected from accidental modification and is not stored with the page definition. 

Perhaps such regions could also have Dynamic Actions associated with them which are automatically included on a page which references the region. 

Think of this feature as turbocharged UI defaults, for an order of magnitude greater developer productivity, with even greater savings on maintenance effort.

Thanks for considering this suggestion.

This would definitely be an amazing feature, would love to see this in a future release!

Yes, we need embedded region components that can be referred to from multiple pages.

Is there any hope of seeing this feature implemented in the next APEX release?

I wanted to have an “address” shared component I could just drop into multiple pages to allow display and editing of addresses in a standardised way. Sounds like this is exactly what I'd want.
Any update on when it might be implemented?

Yes, this is needed feature. possibility to create just regions that are not tied directly to any page but can be used in pages. and select list component then to choose region for display.. like region display selector is but with query option and select list or popup lov layout.

I agree, this is a fantastic idea, one which I have seen implemented in other low-code solutions such as OutSystems (called “blocks”). This would very much so enhance productivity and ability to reuse code, and yes, a reusable region should have inputs and outputs to communicate with the parent page.