Abstract Electronic textiles require rechargeable power sources that are highly integrated with textiles and garments, thereby providing outstanding durability and washability. In contrast, present power sources fabricated using conventional ex situ strategies are difficult to integrate with clothing and can degrade during garment washing. Here, a new manufacturing strategy named additive functionalization and embroidery manufacturing (AFEM) is reported, which enables textile‐based supercapacitors (TSCs) to be directly fabricated on woven, knitted, and nonwoven fabrics. The additive principle of AFEM allows developing TSCs with different types of electrode materials, device architectures, pattern designs, and array connections. High‐machine‐speed, programmable‐design industrial embroidering equipment is used to fabricate TSCs with high areal energy storage and power capabilities, which are retained during many cycles of severe mechanical deformation and industrial laundering with waterproof encapsulation.