A new report has ranked Australia’s worst-performing domestic and international flight routes.

Travellers flying out of Darwin may want to build some extra buffer into their itineraries. New research has revealed the most delayed flight routes in Australia, with some services arriving nearly an hour late on average – and the Northern Territory capital features three times in the top 10.

The Delay to Departure Report , published by business communications platform Esendex Australia, analysed hundreds of domestic and international routes from Australia’s busiest airports over the past year, using Flightradar24 data to compare scheduled versus actual arrival times.

Darwin to Groote Eylandt tops the list with an average arrival delay of 46 minutes – the worst result of any route in the country. The 10 most delayed domestic routes are:

1. Darwin – Groote Eylandt: 46 minutes
2. Alice Springs – Perth: 37 minutes
3. Darwin – Townsville: 36 minutes
4. Newcastle – Perth: 33 minutes
5. Perth – Kununurra: 26 minutes
6. Adelaide – Broken Hill: 25 minutes
7. Brisbane – Charleville: 24 minutes
8. Darwin – Elcho Island: 23 minutes
9. Brisbane – Weipa: 22 minutes
10. Launceston – Melbourne: 18 minutes

On international routes, Brisbane to Port Moresby, Papua New Guinea takes the top spot with an average 27-minute delay – followed by Melbourne to Delhi at 25 minutes. Melbourne features three times on the international list in total. The most delayed international departures from Australia are:

1. Brisbane – Port Moresby, Papua New Guinea: 27 minutes
2. Melbourne – Delhi, India: 25 minutes
3. Perth – Tansonnhat, Vietnam / Sydney – Christchurch, New Zealand: 19 minutes
4. Perth – Kuala Lumpur, Malaysia / Brisbane – Honiara, Solomon Islands: 18 minutes
5. Melbourne – Los Angeles, USA / Melbourne – Colombo, Sri Lanka: 15 minutes

Jonathan Walsh, General Manager at Esendex Australia, said the downstream impact of delays is often underestimated.

“Delayed flights can have a real knock-on effect for travellers, particularly on routes where people are relying on onward connections, ground transport, or tight schedules at the other end," he said.

“Disruption is often unavoidable, but how that disruption is communicated makes a significant difference. Clear, timely updates help travellers make informed decisions, reducing stress and regaining a sense of control when plans change."

The report analysed 185 domestic routes across Australia’s major airports, plus 80 international routes from the country’s four busiest airports. On-time performance was measured against a 15-minute threshold. Data is current as of January 2026.