Of uncertain origin. It is found in Old French as Yolande, of which this is a Latinate form. It may be ultimately of Germanic origin, but if so it has been altered beyond recognition. It is also sometimes identified with the name of St Jolenta (d. 1298), daughter of the king of Hungary.
Spanish: habitational name from Las Mestas in Cáceres province, or Castilianized form of Asturian-Leonese Les Mestes, name of a town and several villages in Asturies, all named with the plural of mesta ‘common (sheep) pasture’ (from Latin mixtas, past participle (plural) of miscere ‘to mix’, ‘to mingle’).