This article examines the social control embodied and enacted in the practices of sending and receiving mocking valentine cards in the Victorian era. Particularly popular in the period 1840–80, cheaply printed and cheaply sold ‘mock’ or ‘mocking’ comic valentines were the inverse of their better-known sentimental print partners. Usually featuring a crude caricature, intended to represent the recipient, and a satirical accompanying verse, such cards had a much wider network than today’s cards. Mocking valentines covered a vast range of ‘types’ and could be sent to neighbours, colleagues and members of the local community as well as to wanting and unwanted partners. Each was designed to highlight a particular social ill, from poor manners and hygiene to pretentiousness and alcoholism, sometimes with astonishing cruelty. As such, for all their purported comical intention, these printed missives critiqued behaviour that deviated from social norms, and could chide, shame and scapegoat. Within the context of a permissive festival atmosphere, the cards functioned as a kind of moral policing; in their anonymous character, they could speak on behalf of many; under the cover of humour, they exercised a collective social control. This article will examine the particular historical conditions of such cards’ production and consumption, with particular reference to a large case study of previously unanalysed examples. Examining debates about industrialisation – where emerging commercial print media would be accused of creating new immoral markets – against the pre-existence and endurance of popular customs of the carnivalesque and their ‘licence to deride’, this article applies ideas from Bakhtin, Zemon-Davies, Stallybrass and White to explore laughter as a social weapon in the transgressive space of the insulting valentine.