Sharif Masahor bin Muhammad Al-Shahab, also written as Syed Mashhor and commonly known as Syarif Masahor, or Sharif Masahor in Malayan contexts, (died 1890 in Selangor) was a famous Malay rebel of Hadhrami descent in Sarikei, Sarawak state, Malaysia during the Brooke White Rajahs era in that state. Later, he played an important role in the Klang War.