Flights will mostly affect Launceston on Saturday. Cancelled flights affect passengers both going to and from Melbourne.

Hobart is also impacted, with passengers seeing two flights cancelled on Friday, four on Saturday and 10 on Sunday.

Nationally, more than 100 domestic flights will be cancelled, but Jetstar international flights won't be affected.

Jetstar's travel alerts say the disruptions will be in place from December 13 and 20 and relate to airline pilots striking actions.

The company is urging customers to make sure their contact details are up to date but are saying if flights are cancelled passengers will be looked after.

"If your flight is cancelled or delayed by more than three hours we'll look after you. You will be offered the choice of an alternate flight or a refund," they said.

"For customers who have to overnight away from home as a result of this disruption we will also offer accommodation and meals to a specified value."

Jetstar Group chief executive Gareth Evans said the work stoppages are completely unjustifiable and timed to hurt travellers at the busiest time of the year.

"To minimise the impact on customers by the four-hour stop-work periods, we are consolidating some services, up-gauging aircraft, re-timing flights and Qantas and QantasLink will operate a number of supplementary services," he said.

"Overall, Jetstar will cancel 44 services on Saturday 14 December and 46 services on Sunday 15 December and Jetstar will contact impacted customers from today."

On average Jetstar operates about 370 flights a day.

"We expect to get 95 per cent of our customers on their way on the same day," he said. "Any customers travelling from 13 December to 20 December can also request a full refund prior to flying."

FAST FACTS:

The pilots are striking as part of a campaign demanding a pay rise of 3 per cent a year and improved working conditions.

"If we accept an effective 15 per cent net increase in pay that the union is demanding, there will be significant upward pressure on the low fares our customers rely on and we will be forced to review our investment in new aircraft and new destinations," Mr Evans said.

"We remain committed to reaching a new agreement to support the great work our people do every day, but not any cost. Strong arm action from the AFAP will not change our position on this."

Find out if your flight is effected here.