The average cost of a round-trip flight to Niagara Falls is $200. The most popular month is January when flights are $250 on average, and the least popular month is October when flights are $120 on average. Flights in April cost an average of $200. The cheapest day to fly from Toronto (YYZ) to Niagara Falls (IAG) is Saturday with an average price of $242 for roundtrip travel using Korean Air in March. The most popular departure city from Toronto International Airport (YYZ) for these cheap tickets is Toronto Pearson International Airport (YYZ). The least expensive departure airport for passengers traveling from Greater Toronto Area / Hamilton Region, Ontario would be Buffalo Niagara International Airport (BUF).