Abu Abdullah Muhammad ibn Abdullah al-Hakim al-Naysaburi (321-405 AH / 933-1014 CE) was a leading hadith scholar of Nishapur and compiler of Al-Mustadrak ala al-Sahihayn, a major hadith collection containing hadiths that meet the criteria of Bukhari and Muslim but were not included in their Sahihs. He authored over 1,500 works and also wrote Ma'rifat Ulum al-Hadith, an important treatise on hadith sciences.