The Taifa of Mértola is a medieval taifa kingdom that exists in what is now southeastern Portugal for three distinct periods: from 1033 to 1044, from 1144 to 1145 and from 1146 to 1151.

From 1044 until 1091 it is under the forcible control of Seville, by Abbad II al-Mu'tadid.

Its short-lived history ends in 1151, when it was finally conquered by the Almohads.