社会主义社会或西方马克思主义社会主义，一种社会型态，指用马克思主义理论指导，重视社会福利，采用财产公有制，通常是共产主义政党专政、工人阶级领导的社会。按照马克思主义理论，社会主义社会是资本主义社会向共产主义社会的过渡性社会型态。在社会主义社会，经济成果是根据按劳取酬的原则分配。

在中国被使用的科学社会主义是由恩格斯提出的，并归名于马克思主义的“继承”。

In Marxist theory, socialism, also called lower-stage communism or the socialist mode of production, refers to a specific historical phase of economic development and its corresponding set of social relations that supersede capitalism in the schema of historical materialism. The Marxist definition of socialism is a mode of production where the sole criterion for production is use-value and therefore the law of value no longer directs economic activity. Marxist production for use is coordinated through conscious economic planning, while distribution of economic output is based on the principle of to each according to his contribution. The social relations of socialism are characterized by the working class effectively owning the means of production and the means of their livelihood, either through cooperative enterprises or by public ownership or private artisanal tools and self-management, so that the social surplus accrues to the working class and society as a whole.