Healthcare workers, teachers, civil servants and bus and train drivers are among those taking part in strikes with members of 16 unions involved.
There was a strong turnout of workers around the local picket lines, despite the bitterly cold weather.
Here are some of the scenes as workers join the Province-wide show of strength.

17. Strike action
Portadown Railway Station Park and Ride car park was almost deserted on Thursday morning as rail services were cancelled due to the public sector strike. PT03-250. Photo: Tony Hendron

18. Strike action
Tannaghmore PS, Lurgan EA workers pictured during Thursday's strike. Photo: Craigavon Trades Council

19. Strike action
Lismore Comprehensive School EA workers take part in the strike. Photo: Craigavon Trades Council

20. Strike action
Staff from Brownlow College Craigavon on the picket line. Photo: Craigavon Trades Council