市场划分（英语：Market segmentation，台湾译作「市场区隔」）是经济学和市场学的一种概念，指将个人或机构客户按照一个或几个特点分类，使每类具有相似的产品服务需求。一个真正的市场划分满足以下所有标准：各个划分不同（不同划分有不同需求），同一个划分内部相同（具有相同需求），对市场刺激做出相似回应且对市场干预有反应。当具有相同产品服务需求的消费者被分成不同组支付不同价格时也使用这个词。大致可以把它们认为是对同一个词的“正面”使用和“负面”应用。

Market segmentation is a marketing strategy which involves dividing a broad target market into subsets of consumers, businesses, or countries that have, or are perceived to have, common needs, interests, and priorities, and then designing and implementing strategies to target them. Market segmentation strategies are generally used to identify and further define the target customers, and provide supporting data for marketing plan elements such as positioning to achieve certain marketing plan objectives. Businesses may develop product differentiation strategies, or an undifferentiated approach, involving specific products or product lines depending on the specific demand and attributes of the target segment.