在软件工程中，一个反面模式（anti-pattern或antipattern）指的是在实践中明显出现但又低效或是有待优化的设计模式，是用来解决问题的带有共同性的不良方法。它们已经经过研究并分类，以防止日后重蹈覆辙，并能在研发尚未投产的系统时辨认出来。

Andrew Koenig在1995年造了anti-pattern这个词，灵感来自于GoF的《设计模式》一书。而这本书则在软件领域引入了“设计模式”（design pattern）的概念。三年后antipattern因《AntiPatterns》这本书而获得普及，而它的使用也从软件设计领域扩展到了日常的社会互动中。按《AntiPatterns》作者的说法，可以用至少两个关键因素来把反面模式和不良习惯、错误的实践或糟糕的想法区分开来：

An anti-pattern (or antipattern) is a common response to a recurring problem that is usually ineffective and risks being highly counterproductive. The term, coined in 1995 by Andrew Koenig, was inspired by a book, Design Patterns, which highlights a number of design patterns in software development that its authors considered to be highly reliable and effective.