Shaykh Shekna Ahmeda Hamahullah ben Muhammad ben Seydina Umar (born 1882) was a Sufi Muslim religious leader, born in French Soudan (modern Mali) and died in France after being arrested and sent into exile in 1933 by the colonial government of French West Africa. While not the founder, he was the spiritual leader of a militant reform movement of the powerful Tijaniyyah sufi ṭarīqah (order, path, brotherhood), which has popularly taken his name, as Hamallayya or Hamallism.