沙文主义（英语：Chauvinism）原指极端的、不合理的、过分的爱国主义（因此也是一种民族主义）。如今的含义也囊括其他领域，主要指盲目热爱自己所处的团体，并经常对其他团体怀有恶意与仇恨。

词源是拿破仑手下的一名士兵尼古拉·沙文（Nicolas Chauvin），他由于获得军功章对拿破仑感恩戴德，对拿破仑以军事力量征服其他民族的政策狂热崇拜。而“沙文主义”这个名词则首先出现在法国的一部戏剧“三色帽徽”中，以讽刺的口吻描写沙文的这种情绪。后来这个词被广泛应用，如大国沙文主义、民族沙文主义等，还曾被女权运动的领袖用于“男性沙文主义”（相当于汉语中的“大男子主义”）。英语中有一个对等的词，是Jingoism。所以经过演变，如今“沙文主义”这个词在英语中更多场合中指种族歧视与性别歧视，尤其是后者。

Chauvinism is an exaggerated patriotism and a belligerent belief in national superiority and glory.

According to legend, French soldier Nicolas Chauvin was badly wounded in the Napoleonic wars. He received a pension for his injuries but it was not enough to live on. After Napoleon abdicated, Chauvin was a fanatical Bonapartist despite the unpopularity of this view in Bourbon Restoration France. His single-minded blind devotion to his cause, despite neglect by his faction and harassment by its enemies, started the use of the term.