Compatibility of Apple Mouse with older iMac

You need to be more specific by identifying the Apple Mouse you are referring to. Once you have done that, then simply Google the following: "Apple Mouse XXXXX tech specs" and then review the tech specs for that mouse to see if it supports the version of Mac OS on your "older iMac."

Also, if you are using USB to connect the mouse then compatibility isn't an issue, just about ANY USB mouse will work with your "older iMac."

Both Belkin & Logitech make 3-button USB mice for under $10 that would work fine.

Was looking around Amazon and they even have a compatible Logitech wireless mouse for under $10.

If it was me I would use a regular mouse anyhow the magic mouse never works right for me atleast it has some weird lag issue that doesn't seem to correct itself. It's the worst piece of hardware Apple makes. The trackpad is wonderful but depending on how old you are talking with iMac BLE might not be supported.

FWIW, the current Magic Mouse (USB) requires Sequoia 15.1 or later.

Your welcome.