Alan Donnelly, a member of Aberdeen City Council, denied kissing and touching a man who was working at an event in the city.
A three-day trial heard one of the victim's bosses say he was 'trembling' when he reported the incident.
The 65-year-old was placed on the Sex Offenders Register in December and resigned from the Conservative party.
Sheriff Ian Wallace previously told the court he was “satisfied” there was a “sexual motive” behind the veteran politician’s actions.
Now there are fresh calls for Donnelly to resign.
'He should resign today'
Aberdeen's Liberal Democrat group leader Ian Yuill said “Hopefully this sentence will help give Councillor Donnelly’s victim some closure.
“Councillor Donnelly should have resigned as a councillor on the day he was convicted. He should have resigned when the council’s Urgent Business Committee urged him to do so on 19th December. He should resign today.”
“Even Councillor Donnelly must understand he cannot possibly do the job of a councillor as a convicted sex offender. His failure to resign shows complete contempt for the Aberdeen’s citizens, Aberdeen City Council and in particular the residents of the Torry/Ferryhill ward.”