I was looking for the proper way to convey the idea of someone being a defender of people's rights,freedoms, and safety. In this context "Man" would be the same as "mankind" or "people." Maybe "Defender of the people" would be a more proper phrasing in English, but I was looking for something more concise. Thank you!
To my ears, defensor hominum would mean someone who defended the existence of human beings. For the political aspect, I'd go with defensor populi, nicely paralleling such concepts as vox populi. For the "people" as state, look no further than Rome's motto: *Senatus Populusque Romanus*, or even Cicero's res publica res populi.
See the Lewis and Short entry on populus.
I'd also second fdb's note of vindex, giving you vindex populi as the best way to convey what you want to say in Latin.
One standard title for British monarchs is dēfēnsor fideī, "defender of the faith". So in reference to that I'd take dēfēnsor as your first word. And the standard word for "of men" (as in "humans", not "adult males") is hominum. So I'd say dēfēnsor hominum.
(You can include the macrons, the little bars over some vowels, or omit them. They represent a pronunciation distinction that disappeared in later Latin.)
"Defensor" is certainly not wrong, but I think "vindex" somehow sounds more Roman. See the quotations here:
(Adding this as a separate answer since it's very different from my first one.)
If you are interested in using Greek instead of Latin, the word Ἀλέξανδρος (Alexandros; Alexandrus in Latin) literally means "defending men" or "defender of men". It was an epithet of the goddess Hera as well as a name, made famous by Alexander the Great.