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.
French: from the plural of jardin ‘garden’ (Old French jart), with the preposition and definite article des ‘from the’; a topographic name or a habitational name from any of numerous minor places so named. In the U.S., this name was often translated as Gardner.