Like all Martians, J'onn has a somewhat cold and stoic demeanor. He has very restricted emotional expressions. J'onn typically acts as the voice of reason in the Justice League and is one of the wisest leaders within the hero community.

In addition to his other abilities, Martian Manhunter has the power to heal himself and others. He has been shown to regenerate his own cells and heal his injuries quickly, and can also use his telepathy to heal the mental and emotional wounds of others.