thumb|right|Residence of Khaled Efendi al-Atassi, the head of The Atassi House, built in 1893
al-Atassi () is a prominent Syrian Arab family of Hashemite origin, descending from Husayn ibn Ali. The presence of the family in Homs, Syria dates back to the 15th century AD, during which the family's ancestors had arrived from Hadhramaut in Yemen after travelling through the Hejaz and Anatolia. In modern times, members of the family led the national movement against the French mandate. The power and prestige of the family reached an apex at the formation of the modern Republic of Syria in 1936, when its second head of state, Hashim al-Atassi was elected president. Two out of the seven members of the constitutional assembly who drafted the first constitution of Syria in 1919 were prominent scions of the al-Atassi family, Wasfi al-Atassi and Hashim al-Atassi. Two more scions, Lu'ay al-Atassi and Nureddin al-Atassi, were in turn installed as heads of state in the 1960s. Family members included magistrates, governors, ambassadors, heads of political parties, military officers and other public officials throughout Ottoman and modern times.
Background
thumb|left|Tomb of Sayed Ali Bin Khalil Al-Atassi, who died in 1508, located in the Atassi Mosque, Homs
thumb|right|Tombstone of Sayed Saleh Al-Sayed Suleiman Al-Atassi, who died in 1782, located in the Atassi Mosque, Homs
The oldest mention of the family was in a religious manuscript, copied in service to one the family ancestors, Sheikh Sayyid Ibrahim bin Ahmad Al-Atassi, who was named a Imam by Prince Toghan bin Seqlesiz, a prince of the Turkmen.
The family's ancestor, Sayyid Ali ibn Khalil al-Attas was a scion of the al-Attas family of the Ba 'Alawi sada of Hadhramaut in Yemen. He had embarked on a journey towards the Hejaz, and from there had moved to Anatolia where he had married a Turkmen woman. Later he and his sons would settle in the city of Homs in Syria. Ali ibn Khalil al-Attas, was buried in 1508 in a tomb inside a mosque which later became known as the Atassi Mosque. The tomb still exists today.
The name al-Atassi evolved from the word "العطاسي" (from "العطاس," meaning "the sneezer" in Arabic) which later changed to "الأطاسي" then to "الأتاسي" or Atassi. This name originates from a nickname of Sayyid Umar ibn Abdurrahman al-Saqqaf, a renowned Sufi saint of Hadhramaut from whom the al-Attas family of Hadhramaut descends. It is said that Umar al-Saqqaf had sneezed and praised God while he was in his mother's womb, from then on he was called 'al-Attas'. Umar al-Saqqaf was a descendant of Sheikh Abdurrahman al-Saqqaf who descended from Faqih al-Muqaddam Sayyid Muhammad ibn Ali Ba 'Alawi, a Sharif scholar descended from Ali al-Uraydi and Husayn ibn Ali through Ahmad al-Muhajir.