耶拿和奥尔斯塔特的两场战役是指发生于1806年10月14日，在现今德国萨勒河以西的高原，拿破仑一世率领的法军和腓特烈·威廉三世率领的普军之间的战斗。法军6天之内便瓦解普鲁士主要作战力量，而普军的惨败令普鲁士于动员作战后仅19日，就被迫退出第四次反法同盟，直至1813年才重新参加第六次反法同盟。法军亦摧毁当时曾经风行一时的线式作战，改写了欧洲陆战的战术原则。

The twin battles of Jena and Auerstedt (older name: Auerstädt) were fought on 14 October 1806 on the plateau west of the river Saale in today's Germany, between the forces of Napoleon I of France and Frederick William III of Prussia. The decisive defeat suffered by the Prussian Army subjugated the Kingdom of Prussia to the French Empire until the Sixth Coalition was formed in 1812.