An ex parte hearing or ex parte relief refers to a situation in which the judge only hears from one party to a dispute before making a decision on some limited issue being presented to the court. Because fairness and due process of law generally require both sides of a dispute to receive notice of a hearing and the opportunity to be heard at the hearing, there must be an emergency situation in which harm that cannot be undone (irreparable harm) will occur if the court does not act immediately—without giving the other party notice and the opportunity to be heard on the disputed issue.

Emergency matters that justify ex parte relief might include the theft of trade secrets by a former employee, or, in a child custody dispute, removing the child from the state, domestic violence, drug and alcohol abuse, sexual abuse of the child, and other situations that put the child in immediate danger.

In California, ex parte hearings and relief are legal procedures where the court may make a decision after hearing only from one party, typically in urgent situations where waiting for a standard hearing could result in irreparable harm. These hearings are an exception to the general rule that both parties should be notified and given the opportunity to be heard. California law allows for ex parte relief in various emergency situations, such as preventing the immediate removal of a child from the state in custody disputes, or addressing immediate risks like domestic violence or abuse. The party seeking ex parte relief must notify the other party about the hearing, usually at least 24 hours in advance, unless the court specifically allows for a shorter notice period due to the urgency of the situation. The applicant must also demonstrate the potential for irreparable harm and that they have made reasonable efforts to notify the other party. The court's decision in an ex parte hearing is typically temporary, with a full hearing scheduled later to ensure due process.