H&K can refer to:
Heckler & Koch, a German weapons manufacturing company Hill & Knowlton, an American PR consulting company Hughes & Kettner, a German brand of guitar and bass amplifiers, cabinets and effects processors Harold & Kumar, a series of stoner comedies and its titular characters Harold & Kumar Go to White Castle, a 2004 film Harold & Kumar Escape from Guantanamo Bay, its sequel Eric Harris and Dylan Klebold, American mass murder duo Hampstead and Kilburn, a UK parliament constituency The Calcium H and K lines, a pair of violet spectral lines "H-K (Hunter-Killer)", song by Fear Factory from the album Demanufacture, 1995