Spanking is a form of corporal punishment involving the act of striking, with either the palm of the hand or an implement, the buttocks of a person to cause physical pain. The term spanking broadly encompasses the use of either the hand or implement, though the use of certain implements can also be characterized as other, more specific types of corporal punishment such as belting, caning, paddling, and slippering.

Some parents spank children in response to undesired behavior. Adults more commonly spank boys 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, while others permit it when done by a parent or guardian.

Medical organizations discourage its use in favor of healthier discipline strategies. Some research has found correlations between spanking and increased aggression, mental health issues, and decreased obedience in children, however findings have been inconsistent, and correlational research suffers from confounding explanations. A 2024 analysis of previous studies found that spanking accounted for less than 1% of changes in child outcomes, concluding that harm caused by spanking had been overstated.

In American English, dictionaries define spanking as being administered with either the open hand or an implement such as a paddle. Thus, the standard form of corporal punishment in US schools (use of a paddle) is often referred to as a spanking. In North America, the word "spanking" has often been used as a synonym for an official paddling in school, and sometimes even as a euphemism for the formal corporal punishment of adults in an institution.

In British English, most dictionaries define "spanking" as being given only with the open hand. In the United Kingdom, Ireland, Australia, and New Zealand, the word "smacking" is generally used in preference to "spanking" when describing striking with an open hand, rather than with an implement. Whereas a spanking is invariably administered to the bottom, a "smacking" is less specific and may refer to slapping the child's hands, arms, or legs as well as its bottom.

The main reasons parents give for spanking their children are to make children more compliant and to promote better behavior, especially to put a stop to their children's apparent aggressive behaviors. ^{[citation needed]} However, research has shown that spanking (or any other form of corporal punishment) is associated with the opposite effect. When adults physically punish children, the children tend to obey parents less with time and develop more aggressive behaviors, including toward other children. This increase in aggressive behavior appears to reflect the child's perception that hitting is the way to deal with anger and frustration.

There are also many adverse physical, mental, and emotional effects correlated with spanking and other forms of corporal punishment, including various physical injuries, increased anxiety, depression, and antisocial behavior. Adults who were spanked during their childhood are more likely to abuse their children and spouse.

The American Academy of Pediatrics (AAP), Royal College of Paediatrics and Child Health (RCPCH), and the Royal Australasian College of Physicians (RACP) all recommend that no child should be spanked and instead favor the use of effective, healthy forms of discipline. Additionally, the AAP recommends that primary care providers (e.g., pediatricians and family medicine physicians) begin to discuss parents' discipline methods no later than nine months of age and consider initiating such discussions by age 3–4 months. By eight months of age, 5% of parents report spanking and 5% report starting to spank by age three months. The AAP also recommends that pediatricians discuss effective discipline strategies and counsel parents about the ineffectiveness of spanking and the risks of harmful effects associated with the practice to minimize harm to children and guide parents.