Fr Kevin Carter is accused of telling the boy to stand against a wall before taking aim with a civil war style musket.
Bergen County prosecutors claims the priest, from St Margaret of Cortona Roman Catholic church in Little Ferry, was unhappy that the boy supported the rivals of his team, the New York Giants.
"As he raised his weapon and pointed it at the boy, he said, 'I'm going to shoot you," prosecutor John Molinelli told NBC 4 New York on Friday.
The eight year old was unharmed in the alleged incident but the priest faces a charge of endangering the welfare of a child and aggravated assault.
"The young boy was apparently a fan of a particular football team, the priest was not. So perhaps we have indication it started out as that," added the prosecutor.
"There's no such thing as joking around with a weapon when you're dealing with an eight-year-old kid."
The Guardian reports a parishioner reported the priest to authorities.
Police claim to have found ammunition and gunpowder after searching the priest's house.
He's been released on $15,000 bail.