纹章学（法文：Héraldique；德文：Heraldik；英文：Heraldry）是西方一门研究纹章的设计与应用的学问。纹章学一词源自「传令官」（古法语：heraut, hiraut），据说在中世纪的马上比武大会上，骑士全身披挂，全靠盾牌上的纹章才搞得清谁是谁，大会上的传令官就凭纹章而向观众报告骑士的比武情况（有点像今日的体育旁白），渐渐「传令官」成了「纹章专家」的代名词，纹章学一词也就由此衍生。纹章的构图、用色都有严格的规定，其研究除了作为文化史的一部分，还有助于历史考证，例如用于断定宗谱及鉴定艺术品、文物的年分。

Heraldry (/ˈhɛrəldri/) is a broad term, encompassing the design, display, and study of armorial bearings (known as armory), as well as related disciplines, such as vexillology, together with the study of ceremony, rank, and pedigree. Armory, the most familiar branch of heraldry, concerns the design and transmission of the heraldic achievement, more commonly known as the coat of arms, usually consisting of a shield, helmet, and crest, together with any accompanying devices, such as supporters, badges, heraldic banners, and mottoes.