Download Google Fonts from:
Create a .fonts directory in home using the terminal and the command:
mkdir ~/.fonts
Unzip the contents of the downloaded file (approx. 350MB) into the newly created .fonts directory with the command:
cd ~/.fonts; unzip ~/Downloads/master.zip
Regenerate the font cache command:
sudo fc-cache -fv
If you want new fonts to be loaded into already open applications, you must close and reopen them.
Now you need to have all the Google fonts available in all Linux system applications.