Adelaide, Countess of Vermandois

Adelaide (Adélaïde in French; died 23 September 1120) was suo jure countess of Vermandois and Valois from 1080 to 1102.

Adelaide was the daughter of Herbert IV of Vermandois and Adele of Valois.

By 1080, Adelaide married Hugh, son of the Capetian King Henry I of France and younger brother of Philip I of France. Hugh became Count of Vermandois, following Adelaide's father's death.

In 1104, Adelaide married Renaud II, Count of Clermont-en-Beauvaisis. By this marriage, Adelaide had a daughter, Margaret of Clermont.

In 1102, Adelaide was succeeded by her son, Ralph I. Adelaide died in 1120, being the last Carolingian to hold the County of Vermandois.

Issue Adelaide and Hugh had: Matilda , married Ralph I of Beaugency Beatrice , married Hugh IV of Gournay Elizabeth of Vermandois, Countess of Leicester, (died 1131) married, firstly, Robert de Beaumont, 1st Earl of Leicester and secondly, William de Warenne, 2nd Earl of Surrey Ralph I, Count of Vermandois Constance, married Godfrey de la Ferté-Gaucher Agnes , married Boniface of Savone Henry (died 1130), Lord of Chaumont en Vexin Simon (died 1148), bishop of Noyon and Tournai William

Adelaide and Renaud had: Margaret of Clermont