The line was already a kilometre long by 7:30 a.m. local time ahead of a draw Wednesday night that could be worth $2.5 million or more.
The province has declared the ace of spades must be drawn, and there could be multiple draws until someone is declared the winner.
There are eight cards remaining in the deck.
Organizers have said they didn't want the draw to interfere with school, which starts in early September in the building next door to St. Kevin's Parish hall.
Organizer Keith Lee said there could be as many as 100,000 people buying tickets for the final draw.
Someone will become a millionaire at Wednesday's Chase the Ace finale