--- title: Tychonoff Product Theorem parent: Compactness grand_parent: General Topology nav_order: 2 --- # {{ page.title }} {% theorem * Tychonoff Product Theorem %} The product of (an arbitrary family of) compact spaces is compact. {% endtheorem %} {% proof %} TODO {% endproof %} Important Application: [Banach–Alaoglu Theorem](/pages/functional-analysis-basics/banach-alaoglu-theorem.html).