Once upon a time I was able to import my Firefox Bookmarks into Safari. Now I can't find any way to do so.
When I select Import Bookmarks in Safari, there is no way to select Firefox, much less its Bookmarks file (when I select Applications folder, Firefox cannot be selected since it's dimmed out).
Anybody? Step by step (if necessary).

I don't have your problem in Safari 10.0.3/Firefox 51.0.1; it will be helpful if you specify version numbers.

Mea culpa. Safari 6.1.6 and Firefox ESR 45.7.0.

What I can't figure out is how I was able (twice and apparently without difficulty) to import old Firefox Bookmarks a couple years back into Safari 5.1.7 (which I just updated to the version given above, which Software Update specifies as the latest update for Lion 10.7.5).

Is Export bookmarks to Safari | Firefox Help helpful?

Indeed it is! Followed the instructions and it worked. Merci.
That said, the imported Bookmarks will only show up as such in a sidebar rather than as the default list of Bookmarks when Show Bookmarks is selected. Is there any way to 'fix' that?

Have you tried drag & drop?

More: Have you searched Safari Help for "import bookmarks"?

I got no useful information from the latter, previously and now.
As to the former, what would I drag and where would I drop it? The only thing I see in the Bookmarks sidebar is the imported Bookmarks file/list.

I was ASSuming that the sidebar contains clickable links that can be dragged to your main list, but if it's strictly text, well...that doesn't seem right...not an importation at all, and...I dunno.

The individual entries are indeed clickable links, but there's no apparent way to get them to the default Bookmarks file so that they drop down in a menu (like Firefox does). {sigh}

In any case thanks for the help. At least I got the bookmarks moved from Firefox to Safari. Keep in mind that I'm only using Safari when Firefox doesn't achieve the desired results.

The only thing I can think of is (if there aren't a million of them) click on each Firefox b/m and hit command-D to create a new one in Safari.

It seems like there ought to be an easy way to do it, or maybe we're misinterpreting "import" and giving it more import than it deserves.

Safari's Developer menu has an option to open the current page in a different browser. Does Firefox have a similar option, or is there maybe an add-on that'll turn the trick?

Not quite a million, but unfortunately there are several hundred bookmarks. So that's a non-starter.
I'll just leave things as is; it's sufficient for my purposes.
Again, many thanks.