Caesar Zeppeli is a hot-blooded but focused man, dedicated to the fight against the Pillar Men.

When he was young, Caesar and his siblings were seemingly abandoned by his father, making him a bitter and extremely violent delinquent. When he was saved by his father from the Pillar Men's trap at the cost of his life, Caesar changes his hate into great pride in his family name.

Caesar is introduced as an arrogant Ripple User looking down on Joseph Joestar's sub-par Ripple ability and missing no occasion to ridicule him and antagonize him in general. However, he reveals himself to be an honorable man, taking pride in his family's tradition of battling evil as well as wishing to avenge the death of his friend, Mark, at the hands of the Pillar Men. When Joseph reveals himself to be an honorable individual as well, their relationship considerably improves. In general, Caesar is respectful to his elders and superiors, most notably his master Lisa Lisa. When it comes to his peers, while he maintains at best shallow relations with this around him when he truly cares for someone it is true love best evidenced by his relationship with Joseph (and pointed it by Messina).

Caesar's other defining trait in his short-tempered personality. He is quick to jump into a fight, even though he knows it is detrimental. Taking great pride in his family name, when Joseph told him that he didn't care about that, Caesar hit him without thinking. That character flaw proved fatal when he made the mistake of rushing to Wamuu's lair alone and then try to finish him off up close. Having great determination, Caesar kept on fighting despite being fatally wounded and made a loud eulogy of the human spirit just before dying. Caesar is nonetheless a very serious person most of the time, zealously fighting the Pillar Men and is exasperated by Joseph's antics.

Caesar is a ladies' man and has a habit of flirting with beautiful women whenever he can, invoking deeply romantic gestures. With his charm and charisma, as well as his own words, he is able to steal the kisses of multiple women with some to minimal interaction beforehand. The only exception to this treatment is Lisa Lisa, despite her noteworthy beauty; She is Caesar's Ripple instructor, whom he claims to respect as much as his own mother.

According to JoJo6251, Caesar dislikes unsophisticated, irresponsible people, and bugs.