I am not sure how Adobe is prioritizing their product development, but this should not be hard to implement and would mean a great improvement in workflow.

How has this not been fixed over 4 years later? And as others are saying—we need pages.

Can't believe this is another basic essential that XD is missing.

Agree with Dan first poster, that we also need pages to organise artboards in our project.

I like the idea of modifier keys for select all in artboard vs cmd-A for everything.

But cmd-A itself could do everything with useful context-sensitivity.

nothing selected: (selects all everywhere like it currently does)
item in artboard selected: (select all content in artboard)
item in a group selected: (select everything in the group)

To generalize: make it select all sibling items to the one currently selected.

definitely a useless feature, and SELECT ALL for all elements inside a single artboard is definitely a useful feature

Seriously, WHY would I select ALL elements across all artboards? I just realized today that Ctrl+A selects EVERYTHING when all I wanted is to make room on the artboard at the very top to add an extra section in the header above everything.

Since I have a pretty long page/artboard, I had to zoom out considerably and drag for a while trying to get everything in. Makes no sense.

Ctrl+A should select everything in active artboard.
Ctrl+Modifier+A should select everything across all artboards.
Ctrl+A if no artboard active should select All Artboards (in case you'd want to export them all for example).

Is this a thing yet? Super annoying to have to drag select all the time :/

Like Stefan said. Which is similar to Illustrator, just backwards. But since the shortcuts are customizable, I would just do it the way AI does for consistency and let folks modify the shortcuts (which is what I did — and continue to do in XD using Apple's System Preferences > Keyboard > Shortcuts settings). You could also implement Pablo's method which makes good logic to me, so long as you have menu items as well for those of us who use shortcuts — and I think there are a lot of us.

I don't know how this hasn't happened yet, but Select All on Artboard should totally be a thing. I need it all the time. End of story.

Often I need to select all elements of the artboard I'm working on, but it acts on all artboards. So in order to be able to move all elements, I'm forced to select by dragging which is not convenient when you have a lot of elements.

I think the optimal behaviour should be like this:
"Select all" acts only on the artboard that is selected.
If you want to select all artobards/elemnts of a document, click on the empty space to deselect artoards and then "select all". I think this is intuitive enough.

Maybe use a modifier key like Alt to toggle the behaviour. Normal shortcut (don't know right now which, is it Cmd-A?) selects everything on the current artboard, normal shurtcut PLUS modifier key selects everything on every artboard.