Nahed Hattar was killed by three bullets as he was going to the courthouse to stand trial, in which he was accused of publishing material that could provoke a sectarian conflict, Efe news reported.
State-run Petra news agency cited security sources as saying that the police has arrested the assailant, but did not reveal his identity.
The 55-year-old Christian writer was arrested last August and spent a month behind bars, but was released on bail earlier this month.
The controversial cartoon, posted on Hattar's Facebook and Twitter accounts, depicts a Muslim asking God to serve him wine and knock before entering his room.
After angry reactions on social media, the Jordanian authorities decided to take legal action against Hattar, who initially went into hiding but later surrendered.
When he appeared before the prosecutor after his arrest, the writer said the cartoon only reflected the behavior of terrorists, but even his usual lawyer refused to defend him in this controversial case.
Meanwhile, the official body responsible for issuing religious edicts in Jordan condemned the cartoon and said that it only increases hatred and sows discord in the country.
