Create new folder in your theme and call it fonts. add your custom font into fonts folder.

copied and past your fonts file into fonts directory.

following this:  moodle/theme/yourtheme/fonts/

In your themes CSS file add the following:

@font-face {
font-family: 'Battambang';
src: url([[font:theme|Battambang.eot]]) format('embedded-opentype'),
url([[font:theme|Battambang.woff]]) format('woff'),
url([[font:theme|Battambang.ttf]]) format('truetype'),
url([[font:theme|Battambang.svg#Battambang]]) format('svg');
}

@font-face {
font-family: 'Kantumruy-Regular';
src: url([[font:theme|Kantumruy-Regular.ttf]]) format('truetype'),
}

Next ADD the name of your font wherever you want that font to be used in your stylesheet.

For example:

#page-header h1 { 
font-family: Kantumruy-Regular,Battambang; 
}