State Superior Court Judge Patricia Costello had delayed ruling on the dispute last week. On Tuesday, she ruled the layoffs of about 50 workers can go ahead.
Tuesday's ruling came after lengthy negotiations failed to reach a resolution on Monday.
Attorneys for city unions said they may appeal Costello's ruling.
Orange Mayor Eldridge Hawkins Jr. said the layoffs are needed to help close an estimated $6 million budget gap.
Hawkins said 10 police officers face layoffs and 16 police supervisors face demotion. A total of 12 firefighters face layoffs or demotion. Additional cuts would be spread around other city departments.