Underscore – Self hosted fonts

Using @import is the way to go, you can do something like this on your stylesheet:

@font-face {
    font-family: FontName;  
    src: url(public_html/your-site/wp-content/themes/your-theme/fonts/FontName-Regular.ttf);  
    font-weight: normal;  
}

Then you simply use it as usual.

p {
    font-family: FontName;
}