The Akhdām (Arabic: الأخدام, romanized: Al-Akhdām, lit. 'the servants'; singular: Khadami), are an Arabic-speaking ethnic or socio-economic group whose members live in Yemen. Although the Muhamashīn are Arabic-speaking Muslims just like most other Yemenis, they are considered to be at the very bottom of the supposedly abolished caste ladder, they are socially segregated from other Yemenis and they are mostly confined to menial jobs in the country's major cities. According to unofficial estimates, the Muhamashīn number is between 500,000 and 3,500,000 individuals.

According to local legends, they are the descendants of 6th-century soldiers from the Kingdom of Aksum during the latter occupation of Yemen in Pre-Islamic Yemen. Today, scholars have predominantly regarded this as a "slanderous myth", asserting that the Akhdam's origins can be traced back to Tanzanian and Swahili captives who were sold during the East African slave trade from the 11th to the 19th century. This perspective is the general view accepted by scholars further supported by DNA testing that reveals a genetic link to Southern Eastern Africa as well as evident connections with the Swahili language, and culture. The exact origins of Al-Akhdam are uncertain. One popular account holds that they are descendants of Ethiopian peoples who accompanied the Axumite army during the latter's occupation of Yemen in the pre-Islamic period. Once the Abyssinian troops were finally expelled, some of the Sudanese migrants are said to have remained behind, giving birth to the Akhdam. This belief, however, seems to be a myth according to Hamud al-Awdi, a professor of sociology at Sanaa University. According to Robert F. Worth, recent waves of immigrants from Ethiopia and Somalia, many of them desperately poor, have fared better than the Akhdam and do not share their stigma as they aren't associated with an army the Yemenis view as oppressors. Out of the deaths reported in an Akhdam shantytown over a year, about half were children under the age of 5, a quarter of whom were in the first month of life. Another theory maintains that they are of Veddoid origin. The group are distinguished from the majority by its members' Negrito-like physical features and stature.

Anthropologists such as Vombruck postulate that Yemen's history and social hierarchy that developed under various regimes, including the Zaydi Imamate, had created a hereditary, caste-like society. Today, the Akhdam people still occupy the very bottom of Yemen's social strata.

In the mid-20th century, the Akhdam people who lived in the vicinity of al-Gades (an exclusively Jewish village) were given the name "Kano" by Jews. While a Shafi'i lowland Muslim would eat from the same dish as a Jew, he would break a vessel touched by one of the Akhdam.

The Akhdam community suffers from extreme discrimination, persecution, and social exclusion from mainstream Yemeni society. The contempt for the Akhdam people is expressed by a traditional Yemeni proverb:

"Clean your plate if it is touched by a dog, but break it if it's touched by a Khadem."

Though their social conditions have improved somewhat in modern times, the Akhdam are still stereotyped by mainstream Yemeni society: they have been called lowly, dirty, and immoral. Intermarriages between non-Akhdam and Akhdam are taboo and virtually prohibited, as the Al-Akhdam are deemed as untouchables. Men who do marry into the community risk banishment by their families.

Today, in Yemen, children born from mixed Akhdam and Yemeni parentage are called muwāldedīn, and are often still discriminated against in society.