Three-hundred discount fares on the Canberra-Melbourne route were offered online in the airline's "return for $1" promotion.

As part of the sale, 14,000 bargain fares for travel between mid-July and mid-September 2017 were available from noon today until noon Saturday, May 13 or until sold out.

The deal enabled customers to travel for just $1 on the return sector of any route the airline flies across Australia, but seats were limited.

At 3.15pm a spokesman for Tigerair said just 34 seats remained from Melbourne to Canberra.

At 5pm he advised the discount fares were no longer available between the Victorian and national capitals.

Tigerair communications chief Vanessa Regan said earlier today the cheap fares were expected to be snapped up quickly.

"One dollar doesn't buy you much these days and the opportunity to return from your holiday for less than the cost of a newspaper or bus ticket is phenomenal when you think about it," she said.

"We are thrilled to continue to enable more people than ever, the opportunity to fly for less."

Canberrans who don't mind travelling from Sydney or Melbourne can still join the online queue for $1 return fares from destinations including Cairns, Perth, Whitsundays, Hobart and Coffs Harbour.