Every so often this question comes up on the Apple Discussions. “How do I take a folder of photos and batch them into one photo per slide in Keynote?” Turns out there’s an easy solution to this that might be so obvious that you’ve never thought about it.
The trick here is, instead of looking for some sort of advanced insert or import function, simply open a folder of photos in the Finder, select all of them (command-A) and drag the whole lot into the slide list on the left hand side of the Keynote window. Keynote will then import all your photos and stick one on each slide.
If you don’t want huge image files floating on your slides, you can also visit the Keynote prefs and check the box next to “Reduce placed images to fit on slides” before you import your photos. This will resize your images to fit on the slide. Thankfully, this feature doesn’t crop your photos, it simply resizes them and leaves either the top and bottom or sides hanging off the edges of the slide if the photo isn’t the same proportion as your slides. One issue with this feature though, is that itÂ permanentlyÂ changes each image, meaning it literally resizes your images and saves a new version inside your Keynote file. So if you were planning on enlarging and cropping some of your images after you import them, you may not want to use this feature.
One other catch on older versions of Keynote is that some versions have issues with the order. Keynote 09 appears to always sort photos on import alpha-numerically, but older versions sometimes would bring the photos in with no apparent order. The solution is to view your photos in List view in the finder and view by name before dragging them into Keynote.