Incompetent evidence is a piece of evidence that is inadmissible because it is irrelevant or immaterial (has no bearing on the case at hand).
However, sometimes the courts do admit incompetent evidence and generally courts do not reverse a trial court in a nonjury case for having admitted incompetent evidence, whether objected to or not, unless all of the competent evidence is insufficient to support the judgment appealed from or unless it affirmatively appears from the record that the incompetent evidence was relied upon by the trial court and induced the court to make an essential finding which would not otherwise have been made. See Thompson v. Carley.
[Last updated in February of 2022 by the Wex Definitions Team]