Judge Anthony Halpin fined Kinsella €250.
The defendant, of Oliver Bond House in Dublin 8, admitted before Tallaght District Court to threatening and abusive behaviour and failing to follow the directions of gardai.
Garda Lisa Prendergast said she was called to a pub in Rathfarnham shortly after 1am on July 17 after reports of a fight.
She said the fight was over but there was a large crowd gathered in the area, and she told them to leave.
The garda said Kinsella became verbally abusive and was told to go. He walked a short distance, to Whitechurch Grove, where he continued to abuse officers.