How do I change fonts and adjust their size?

I've been finding fonts on the internet and installing them on my system.

What's the easiest way to change my fonts? I would prefer an easy to use graphical way, but answers with command line recommendations are also welcome.

Solution 1:

Ubuntu 18.04 and later versions

The latest Ubuntu uses GNOME Shell. You can change the fonts using the "GNOME Tweaks" (gnome-tweak-tool) program.

Install the program using Ubuntu Software:

And change the font and font size.

13.04 - 17.04

For Unity interface users, customisation of fonts can be done using unity-tweak-tool

For 12.04:

For Unity interface users, they have their own tweak-tool. Customisation of Fonts in 12.04 can be done through myunity

Solution 2:

In Oneiric (11.10), I wasn't interested in installing GNOME Shell just to change font sizes. This will do it via command-line:

gsettings set org.gnome.desktop.interface document-font-name 'Sans 10'
gsettings set org.gnome.desktop.interface font-name 'Ubuntu 10'
gsettings set org.gnome.desktop.interface monospace-font-name 'Ubuntu Mono 11'
gsettings set org.gnome.nautilus.desktop font 'Ubuntu 10'
gconftool --set /apps/metacity/general/titlebar_font 'Ubuntu Bold 10' --type STRING

The fontfaces are the same as in default Oneiric, but sized down to what looked like much more manageable sizes.