In sociology, a lifestyle is the way a person (or a group) lives. This includes patterns of social relations, consumption, entertainment, and dress. A lifestyle typically also reflects an individual's attitudes, values or worldview.

Having a specific "lifestyle" implies a conscious or unconscious choice between one set of behaviours and some other sets of behaviours.

In business, lifestyles provide a means of targeting consumers as advertisers and marketers endeavor to match consumer aspirations with products.

The word "lifestyle" apparently first appeared in 1939. Alvin Toffler predicted an explosion of lifestyles ("subcults") as diversity increases in post-industrial societies. Pre-modern societies did not require a term approaching sub-culture or lifestyle, as different ways of living were expressed as entirely different cultures, religions, ethnicities or by an oppressed minority racial group. As such the minority culture was always seen as alien or other. Lifestyles, by comparison, are accepted or partially accepted differences within the majority culture or group. This tolerance of differentiation within a majority culture seems to be associated with modernity and capitalism.

Within anarchism, lifestylism is a belief that by changing one's own personal lifestyle, and by retreating from class struggle, an anarchist society can be formed.

One who is in the "lifestyle" is someone who engages in what is more commonly called swinging. Also called the "alternative lifestyle", people in the lifestyle most commonly are part of a couple; often a married couple. They meet other like-minded couples or occasionally singles to engage in sexual acts. People in the lifestyle meet on various different websites, as well as in private and public clubs.