On Mac you can access to mounted drives through /Volumes but i'm not sure that everything appears there (at least i don't see the CD drive). This directory is hidden by default (Finder don't show it) so obviously QFileDialog too. Since there is no way to access to those drives elsewhere the only workaround is to show hidden files and i think that is not the correct way. Using the native dialog is not acceptable for everyone so we have to find a way to have access to those drives like on windows. We can either put them on the left side bar or we can use the logical "My Computer" view that QFileSystemModel uses for Windows.