打屁股，是拍打他人的臀部屁股以引起暂时性疼痛，但不致造成身体部位伤害的行为。

打屁股通常用来逞惩罚一个人，通常是施打者以空手拍打受罚者的臀部（屁股肉）；更严重的形式则是使用棍子或鞭子作为工具，而不是手。打屁股是管教婴儿、儿童或少年或是青少年最常用的手段之一，它通常由父母、监护人或老师担任施打者。从历史上看，男孩比女孩更常受到此打屁股的惩罚，相对而言男性也较常光屁股打。有些国家已经禁止对儿童打屁股，但大多仍会允许双亲或监护人如此作。

在某些文化中，丈夫对妻子打屁股被视为一种可接受的家法或处罚，不过已经不像以往那么常见。在其他情况下，对成年人打屁股可以视为社交礼仪上的俏皮行为或是一种娱乐型式。

Spanking is a type of corporal punishment involving the act of striking the buttocks of another person to cause physical pain, generally with an open hand (more commonly referred to in some countries as slapping or smacking). More severe forms of spanking, such as switching, paddling, belting, caning, whipping, and birching, involve the use of an implement instead of a hand. Parents commonly spank children or adolescents in response to undesired behavior. Boys are more frequently spanked than girls, both at home and in school. Some countries have outlawed the spanking of children in every setting, including homes, schools, and penal institutions, but most allow it when done by a parent or guardian. Adults may spank other adults as well, often in an erotic context.