How to Install Fonts on a Macintosh. Fonts add creative zing to your documents and can help you express your flair. Installing fonts on a Macintosh is simple - the Macintosh OS doesn't care whether you use PostScript or TrueType fonts.
Locate the fonts you want to install. If you are installing a TrueType font, you need only one file. If you are installing a PostScript font, you will need the printer font and the font suitcase containing the screen font.
Drag the fonts to the System Folder. You will be prompted to allow the fonts to be moved to the Fonts folder. Click OK.
You may need to quit out of certain programs for the new fonts to be available in those programs.