Harmless Error Law and Legal Definition

Harmless error is an error by a judge during the course of a trial which an appellate court finds does not justify the reversal or modification of the lower court's judgment at trial. Harmless errors may include a technical error which has no bearing on the outcome of the trial, or an error that was was followed by a curative instruction (such as allowing testimony and then ordering it stricken and admonishing the jury to ignore it), and others. Often, an appeals court will find an error to be harmless because it is their determination that even though there were errors, the appealing party could not have won in trial in any event. Harmless error is based upon a finding that the error was not significantly prejudicial to the appellant so as to affect the outcome of the case.

Many appellate court opinions set forth a two-step analysis: first, determining if there was indeed error; and second, determining if such error was harmless. In other cases, the opinions address only the issue of whether the alleged error is harmless, without deciding whether an error was indeed committed.