: Developers with an active Apple Developer account can sometimes access older installers via Apple’s “More Downloads” portal.
Before installing macOS Yosemite, ensure that your Mac meets the system requirements: mac os yosemite 10.10 download dmg
: macOS Yosemite 10.10 is no longer supported by Apple. It is not available on the official Mac App Store for new downloads unless previously purchased under your Apple ID. : Developers with an active Apple Developer account