Q: Random order slides in Photos slideshow ?

I can find no such setting.

http://www.apple.com/feedback/macosx.html for feature requests

Glad it isn't just me. This is a pretty basic requirement for slideshows surely!!!

Did they not do any end user testing?!

Always bear in mind that one person's basic feature is another's pointless complexity. Yes there was even a free beta program that anyone could join. Use the feedback link.

Pointless complexity? Sorry, I totally disagree. The iPhoto program had the shuffle feature, and over the years nearly every slideshow application has had it. There's no engineering territory to blaze in devising photos to appear based on a pseudo-random order. No, this was a program management and marketing design not to take the time and money to implement it. Given the slideshow themes, like "Sliding Panels", "Vintage Prints", and others, having no random theme is most conspicuous.

The Smart Album feature is great, you can add multiple clauses with the + button, but sadly there is not an ORDER BY clause. So you can't even mock a random slideshow if you import a set of photos named with GUIDs, and sort by filename.

Be sure to tell Apple what missing features you'd like restored in Photos via https://www.apple.com/feedback/photos.html. The squeaky wheel and all....

Since there are at least a couple of Apple tools which can create static slideshows (iMovie and Final Cut Pro, just off the top of my head), but no current tools that will do random slideshows, I'm not sure how it could possibly be "pointless complexity." Particularly since I don't recall (and can't locate via search) any complaints that iPhoto's random photo order for slideshows was viewed as "pointless" or "complex" by anyone; quite the opposite, there are several questions posted in the iPhotos forums about how to manipulate and maximize this particular feature.

Perhaps you should read what I wrote again.

No thanks, I read it correctly the first time.

Obviously not.

Yep,  iPhoto had the shuffle feature, had it for quite a while. The Photos app on the iPad, iPhone, and AppleTV have the shuffle feature now, meaning that I can open an album in the cloud and play it as a random order slideshow on my little iPhone, my very old iPad, and my Apple TV. But can I open the same slideshow and run it in random on my new, pricey 27" iMac? Nope.

iRaindrop,not just most photo slideshows, but iTunes also has a shuffle feature. I'm really, really annoyed at Apple for dropping the shuffle feature from Photos for the iMac, and as of iOS 9 they've also dropped it from Photos for the iPad. They do glitzy ads marketing all the new features for a new iOS but they never tell you that they're dropping features that you love and have used for years. And once you download the new iOS you're stuck with it, and can't go back Boo Apple.

I hoped I was just not seeing the button, but confirmed with Apple Support yesterday that there is indeed no random/shuffle feature for slideshows in the Photos app. On the iPad there's no solution (I hate you, Apple, for dropping a feature I love). On the iMac the tech support person walked me through setting up a screen saver with a Photos album to use as a slideshow, and I'm pleased with it.

The screen saver does do random order slideshows, but crucially lacks any way to change how long each image is displayed. Another annoying example of Apple-knows-best trumping actual usefulness. I love the screen saver slideshow's Ken Burns-style in shuffle mode, & long wished there was a way to change the display interval, so was delighted when iPhotos gave us that ability. But now Apple, unquestionably NOT knowing best, has taken it away, so it is again impossible to view a Ken Burns style slideshow in shuffle mode with display interval of your own choosing

Why? Ours is not to wonder why; ours is but to buy & buy.