Catholic teachers from schools across the Illawarra gathered at Wollongong's Lang Park for a three-hour strike on Thursday morning to express their frustration at negotiations over salaries and working conditions.
Members of the Independent Education Union (IEU) within the Wollongong diocese are currently in negotiation with the Catholic Commission for Employment Relations (CCER), which represents the Catholic education office.
Speakers at the rally included teachers from Fairy Meadow's Good Samaritan primary school and Bellambi's Holy Spirit College, as well as IEU organiser Les Porter.
They said there was a strong need for teachers to fight for conditions that recognised their commitment to educating students.
Teachers will return to school at midday.
Shellharbour MP Anna Watson attended the rally to show her personal support for their industrial action campaign.
"Four local Catholic schools in my electorate have teachers and support staff in them who are involved in this industrial action," she said.
"I urge the CCER to get back to the negotiating table and bargain over wages and conditions in good-faith.
Ms Watson said Catholic school teachers had not engaged in industrial action for at least a decade.
"It's very clear that the proposed enterprise agreement contains unacceptable terms and conditions to teachers and support staff in Catholic schools in the Wollongong diocese," she said.