HUDDERSFIELD Magistrates Court will open on the day staff walk out on strike.
Staff from one large and one small union voted for their first strike in the service's 800-year history in a dispute over pay.
The day of action will be tomorrow, but people due in court that day must turn up.
Patrick Traynor, area director for the courts service in West Yorkshire, has stressed that the courts will open in the county.
He said: "Magistrates Courts in West Yorkshire will be open on Tuesday, December 20, and - unless notified otherwise - anyone who is due to appear at any of the courts that day should arrive at the time directed."
A spokeswoman added it was unclear exactly how many staff would be on strike at Huddersfield Magistrates Court, but contingency plans had been drawn up.
Staff from back room jobs are likely to plug the gaps to make sure the courts keep running.
In the national ballot, 80% of 7,800 magistrates' courts staff who are members of the Public and Commercial Services Union (PCS) voted for the national strike after what they said was a below-inflation pay offer of 2.2%.
It will involve staff who run the courts and provide advice to magistrates, including clerks, ushers and administrative staff.
Members of the Prospect union, which represents 120 senior legal advisers in magistrates' courts, also voted for strike action.
Rosie Eagleson, PCS national secretary, said: "This overwhelming vote illustrates the strength of feeling among staff who are facing a below inflation cost of living increase.
"Members have made it clear with this historic vote that they will take strike action to secure fair pay and it is high time that management started to negotiate meaningfully in order to avoid serious disruption to the magistrates' courts in England and Wales."