From what I can see from this thread¹, it would seem so:<p>“<i>The last versions of OS 9 were pretty good about right mouse button support. Most mice should work fine.</i>”<p>I would test it myself on my iMac G3 (Summer 2001), but unfortunately, I already upgraded it to Mac OS X v10.4.11 Tiger, and it’s getting active use, so I can’t exactly go downgrading it at the moment.<p>――――――<p>¹ — <a href="https:&#x2F;&#x2F;discussions.apple.com&#x2F;thread&#x2F;1824021" rel="nofollow">https:&#x2F;&#x2F;discussions.apple.com&#x2F;thread&#x2F;1824021</a>