Kyley Harris appeared in Halifax provincial court for sentencing after pleading guilty to the charge in December.
As part of the court's conditions, Harris must complete nine months' probation, is prohibited from drinking alcohol and must complete 30 hours of community service.
He also cannot have direct contact with the victim, unless through a lawyer or with her prior consent.
The court was told Harris struck a woman in the face during a domestic argument on May 9, 2014.
Harris read a statement, telling the court his actions were "inexcusable and disgraceful."
"I made an unforgivable mistake and I am sorry," he said.
Harris said he has apologized to the victim and also regrets letting down those he worked for in the Premier's Office.
He was initially placed on administrative leave with pay following the incident, but was fired a short time later by Premier Stephen McNeil.
McNeil said the termination was necessary because Harris waited four days to tell the government he was facing a charge.
Outside court, defence lawyer Michael Scott said the fact Harris sought counselling on his own for alcohol dependence and anger management played a role in the joint sentencing recommendation.
"He's lost his job, his income and his reputation so now he has the job of sort of rebuilding without having a criminal record encumbering him," said Scott.
Harris is eligible for an absolute discharge on Sept. 1, meaning he will have no criminal record as long as he abides by the court's conditions.