PKN

PKN can mean:
 * A type of fertiliser used in horticulture containing a ratio of phosphorus (P), potassium (K) and nitrogen (N).
 * Pertti Kurikan Nimipäivät, a Finnish punk band
 * A member of the protein kinase family of enzymes
 * PKN1, protein kinase N1
 * Protestant Church in the Netherlands
 * Personal knowledge networking
 * Program Khidmat Negara, Malaysia's National Service program
 * The Palace of Culture and Science, the tallest building in Poland
 * A variant version of the PK machine gun
 * PKN, the IATA code of Iskandar Airport in Indonesia
 * Polish Committee for Standardization, Polski Komitet Normalizacyjny