The term nanny state, used especially in the United Kingdom, is a derogatory term for government intervention, especially in social issues. Nannydom refers to the general way of thinking that can emerge in power hierarchies (even those smaller than states) while practitioners of such behaviour may by called nannycrats.

Policies such as bans on smoking in public places, high taxes on junk food, and anti-pornography laws are often pointed to as an example of a functioning nanny state. Such actions are said to operate on the assumption that the state (or, more often, one of its local authority) has a duty to "protect" the citizenry from their own harmful behaviour.

Conservatives and libertarians tend to use the term to oppose new government regulations, although many traditional conservatives may also advocate paternalism, which some liberals and socialists may regard as much the same.

The city state of Singapore has a reputation as a nanny state, owing to the considerable number of government regulations and restrictions on its citizens' lives. However, Minister Mentor and elder statesman Lee Kuan Yew has said: "If Singapore is a nanny state, then I am proud to have fostered one."