Casualness has perhaps always been present in clothing. Maybe even Julius Caesar’s loose-hung toga, sometimes read as a form of dandyism, was a move familiar in casualwear, changing the vocabulary of the sartorial norm to appear more relaxed, with something of an old-money swagger to it, to enact generational distinction, and to visually challenge the formality of a previous order. Casualness is not the same as informality or the unformed, indeed it is often as consciously put-together and structurally considered as formalwear, but it uses a vocabulary of relaxation of clothing rules, or total disregard for them to symbolize a change in values and generation. While acknowledging that this fashion move has been available and used throughout all clothing history and perhaps across all cultures, this chapter focuses on casualwear becoming a global industry and one of the dominating fashion meta-styles from the 1960s.