The court in Paris also ordered Archbishop Luigi Ventura, 76, to pay nearly $16,000 (13,000 euros) in compensation to four victims for "pain and suffering" and $11,000 (9,000 euros) in legal costs, according to Agence France-Presse.
The conviction also meant the Ministry of Justice automatically registered him as a sex offender.
The archbishop, who was nuncio to France at the time the alleged incidents occurred, has denied the charges against him, and his lawyer said they would be considering an appeal.
The conviction Dec. 16 came after French prosecutors had launched a formal investigation in 2019 into an allegation by a city official that the Vatican diplomat molested him by groping his buttocks. Three other men, including a seminarian, later filed similar complaints of sexual assault or molestation between January 2018 and February 2019. A fifth man, who was also a civil servant, also reported an incident, but did not file a complaint.
After French officials had reported their investigation, the apostolic nunciature in Ottawa, Ont., confirmed it also had received a complaint of sexual misconduct concerning Ventura, who was the apostolic nuncio in Canada from 2001 to 2009.
The archbishop was not present for the Nov. 10 trial or the court's verdict Dec. 16. He had submitted a doctor's note citing the dangers of traveling during a global pandemic.
The Vatican waived the diplomat's immunity in July 2019 in light of the criminal proceedings that had begun against him in France, and Pope Francis accepted the archbishop's resignation "for reasons of age," Dec. 17, 2019, eight days after the archbishop turned 75, the age at which bishops must offer their resignations.
The archbishop had also served as nuncio to Chile for two years, from 1999 to 2001 and, before that, in Ivory Coast, Burkina Faso and Niger from 1995 to 1999.