认知偏误（英语：cognitive bias）或认知偏差、认知偏见是有特定模式的判断偏差，主要是由于人们以根据主观感受而非客观信息创建起主观以为的社会现实所致。认知偏误可导致感知失真、判断不精准、解释不合逻辑、或各种统称「不理性」的结果。

有些认知偏误是广为接受的，认知偏误往往能节省时间，使行动更有效率，因此有时也称作捷思。另一些认知偏误则是人们思维系统的内置局限，容易造成不恰当的心理反应与想法。

近数十年来认知科学、社会心理学、行为经济学快速发展，总结出大量的认知偏误。这些认知偏误很值得研究，因为系统性的错误揭示「感知与判断的背后心理过程」。

A cognitive bias refers to a systematic pattern of deviation from norm or rationality in judgment, whereby inferences about other people and situations may be drawn in an illogical fashion. Individuals create their own "subjective social reality" from their pe****tion of the input. An individual's construction of social reality, not the objective input, may dictate their behaviour in the social world. Thus, cognitive biases may sometimes lead to pe****tual distortion, inaccurate judgment, illogical interpretation, or what is broadly called irrationality.