Here's a listing of
Fonts that carry the GNU public license, which as close to public domain as you're going to get, and can be freely distributed, embedded or even altered.
You may be particularly interested in Baskervald and Isabella.
I'll look for some others when I get a chance.
EDIT: Looking again, it looks like a lot of the other font licenses listed at that website are also free-use licenses of some sort or another. Browse around (I am). They don't make it terribly obvious how to download the fonts, even if you register, so you might just find a font you like, then google it to find its own website, and download link.