Muḥammad bin ‘Abd al-Karīm al-Khaṭṭābī, better known as Abd el-Krim (Arabic: عبد الكريم; 12 January 1882 – 6 February 1963), was a Moroccan political and military leader and the president of the Republic of the Rif. He and his brother M'Hammad led a large-scale revolt by a coalition of Riffian tribes against the Spanish and French Protectorates of the Rif and the rest of Morocco. His guerrilla tactics, which included the first-ever use of tunneling as a technique of modern warfare, directly influenced Ho Chi Minh, Mao Zedong and Che Guevara. He also became one of the major figures of Arab nationalism, which he actively supported.

Muhammad ibn Abd al-Karim was born in 1882 in the settlement of Ajdir, Morocco. He was the son of Abd al-Karim al-Khattabi, a qadi (Islamic judge and chief local leader) of the Ait Youssef ou Ali clan (or Aith Yusif w-'Ari) of the Riffian Ait Ouriaghel tribe. The Ait Youssef ou Ali is part of the two fifths that belong to the Ait Khattab hence the nisba al-Khattabi. He was named qadi in the 1880s by Hassan I.

In Abd el-Krim's memoirs authored by Jacques Roger-Mathieu, Abd el-Krim traces his ancestry to a certain patriarch named Zar'a who originated in Yanbu in the Hejaz, belonging to an Arab tribe known as Ouled Si Mohammed ben Abd el-Krim, from which Abd el-Krim derived his name. Zar'a is believed to have immigrated to the Rif and settled among the Beni Ouriaghel in the 10th century.

The majority of Moroccan and Arab authors consider Abd el-Krim's family to be Arab. Despite this, European authors such as historian Germain Ayache and anthropologist Robert Montagne [fr] assert that Abd el-Krim's family is entirely of Berber origin. Abd el-Krim's ancestry is unclear, as Riffian families did not hold proper documentation regarding their genealogy.

In some instances, Abd el-Krim was attributed ancestry to Umar ibn al-Khattab and Idris II, founder of the city of Fez. Despite this, French colonial authorities claimed that Abd el-Krim "forged an Idrissid ascendance" to gain legitimity due to Moroccan religious tradition. According to Mohammed Azarqan, the foreign minister of the Republic of the Rif, his surname comes from the Aït Khattab clan of the Ait Ouriaghel and has no relation with Umar ibn al-Khattab. Historian María Rosa de Madariaga also denies Abd el-Krim's alleged sharifian lineage.

In a later interview in 1952 with the weekly Akher Saa, Abd el-Krim defined himself as an ethnic Berber and explained that his ancestors were Berbers; he also highlighted the Berber people as "advanced people, who have inherited many civilizations" and that "we speak Arabic, the language of the Quran, and we understand ourselves in Berber, the language of our ancestors".

Abd el-Krim received a customary formative education at a local school in Ajdir and subsequently attended an institute at Tetouan. At the age of 20, he studied for two years in Fez at the Al Attarine and Saffarin madrasas and subsequently enrolled as a student at the University of al-Qarawiyyin, the world's oldest institution of higher education. Both Muhammad and his brother M'Hammad received a Spanish education, the latter studying mine engineering in Málaga and Madrid. Both spoke fluent Spanish and Riffian.

Following his studies, Abd el-Krim worked in Melilla (a Spanish enclave from 1494 to the present day) as a teacher and translator for the OCTAI, the Spanish 'native affairs' office, and as a journalist for the Spanish newspaper Telegrama del Rif (1906–1915). In 1907, he was hired to edit and write articles in Arabic for El Telegrama del Rif, a daily newspaper in Melilla, where he defended the advantages of European—especially Spanish—civilization and technology and their potential to elevate the economic and cultural level of the Moroccan population. In 1910, Abd el-Krim took a position as secretary-interpreter in the Native Affairs Office in Melilla, which brought him into close contact with the Spanish military bureaucracy and the town's civil society and gained a reputation for intelligence, efficiency and discretion.