Joktan or Yoktan (יָקְטָן "little", Standard Hebrew Yoqtan, Tiberian Hebrew Yoqṭān) was the second of the two sons of Eber (Gen. 10:25; 1 Chr. 1:19) mentioned in the Hebrew Bible.

In the Book of Genesis 10:25 "And unto Eber were born two sons: the name of one was Peleg; for in his days was the earth divided; and his brother's name was Joktan."

There is an Arab tradition that Joktan (Arabic: Kahtan) was the progenitor of all the main tribes of Central and Southern Arabia. There are thirteen children of Joktan : Almodad, Sheleph, Hazarmaveth, Jerah, Hadoram, Uzal, Diklah, Obal, Abimael, Sheba (not in Arabia), Havilah (not in Arabia), Jobab (described in Chinese name books), and Ophir (not in Arabia). Seven of them are said to be each the founder of an Arabian tribe.