仿真联合国（英语：Model United Nations，缩写MUN）是一种学术性质活动，藉倣傚精简后的联合国议规举行仿真会议，使与会者了解多边外交的过程，培养分析公民议题的能力，促进世界各地学生的交流，增进演讲和辩论能力，提高组织、策划、管理、研究和写作、解决冲突、求同存异的能力，训练批判性思考、团队精神和领导才能，同时认识不同文化，拓展国际视野，了解各国在历史上或现实中的立场与处境。

模拟联合国活动广泛开展于世界各地的中学生和大学生间，每年全球都会举办数十场国际性的仿真联合国会议，参与人数超过四百万人。

Model United Nations, also known as Model UN or MUN, is an educational simulation and/or academic competition in which students can learn about diplomacy, international relations, and the United Nations. MUN involves and teaches researching, public speaking, debating, and writing skills, in addition to critical thinking, teamwork, and leadership abilities. Usually an extracurricular activity, some schools also offer MUN as a class.