KHD may refer to: KHD Humboldt Wedag, an engineering company that supplies machinery, parts, and services khd, the ISO 639-3 code for Ngkolmpu Kanum language Khorramabad Airport, the IATA code KHD Klöckner Humboldt Deutz AG, a German internal combustion engine manufacturer Kärntner Heimatdienst, a German nationalist advocacy group