A judge may be disqualified from hearing or presiding over a matter in which provable facts suggest the judge has a disqualifying conflict of interest. The related legal process of recusal of a judge is generally based on the perception of impartiality due to circumstances that suggest a conflict of interest—but not to the same degree as the facts that establish disqualification.

The standards for disqualification of a judge vary from state to state, and disqualification is rare. But a judge is generally disqualified in any proceeding in which:

(1) the judge has served as a lawyer in the matter in controversy, or a lawyer with whom the judge previously practiced law served during such association as a lawyer concerning the matter;

(2) the judge knows that, individually or as a fiduciary, the judge has an interest in the subject matter in controversy; or

(3) either of the parties may be related to the judge by affinity or consanguinity within the third degree.

In Washington State, a judge may be disqualified from presiding over a case if there are provable facts indicating a conflict of interest that could affect the judge's impartiality. According to the Revised Code of Washington (RCW) 2.28.030, a judge is disqualified from hearing a matter if they have previously acted as an attorney in the case, or if an attorney with whom they previously practiced law has acted concerning the matter. Additionally, a judge must disqualify themselves if they have a personal or fiduciary interest in the outcome of the case, or if they are related by blood or marriage to a party in the case within the third degree. The process for a judge's recusal is typically initiated by a motion from one of the parties involved, and the judge may also self-disqualify if they recognize a potential conflict of interest. The standard for disqualification aims to maintain the integrity of the judiciary by ensuring judges remain impartial and that justice is administered without bias or the appearance of bias.