Ground handlers from Dnata, who are contracted to Qantas and other airlines, will walk off the job for 24 hours on Monday, September 12, AAP reports.
The industrial action was agreed to by Dnata workers on Friday with some 350 crew to strike.
It follows calls by the Transport Workers Union for Dnata to lift pay and conditions, including minimum guaranteed work hours.
Qantas sacked its own ground crew staff during the height of the COVID-19 pandemic and moved to outsourcing roles to companies such as Dnata.
An airline spokeswoman said the negotiations were a matter for Dnata and the carrier had contingency plans in place to curb disruptions.