Qahtan (or Kahtan) (Arabic: قحطان) and Qahtani (Kahtani) (Arabic: قحطاني) or with the definite article al- as Al-Qahtani (Al-Kahtani) (Arabic: القحطاني) meaning coming from Qahtan may refer to:
Qahtan (tribe), an Arab tribal confederation in Saudi Arabia
Qahtanite or Qahtani, Arabs who originate from the southern region of the Arabian Peninsula, especially from Yemen