Change font of text next to radio button?

From the official doc:

Typeface typeface = getResources().getFont(R.font.myfont);
textView.setTypeface(typeface);

You set the font to the text next to a RadioButton the same way you do to a TextView:

RadioButton rb  = (RadioButton) findViewById(R.id.radiobutton);
Typeface font = Typeface.createFromAsset(getAssets(), "SF_Cartoonist_Hand_Bold.ttf");
rb.setTypeface(font);