Sheikh Muhammed Osman Sirajeddin Naqshbandi (Arabic: الشيخ مُحَمَدْ عُثمان سراجُ الدّین نَقشبَندی), Seyyid Osman Sirajeddin-i Thani or Baba Shah (1314 AH/1896 AD, Biyara, Kurdistan) – 1418 AH/1997 AD, Istanbul, Turkey) was an Islamic scholar and Naqshbandi mystic.