Eckard I (Ekkehard; died 30 April 1002) was Margrave of Meissen from 985 until his death, the first margrave of the Ekkehardinger family that dominated Meissen until the extinction of the line in 1046.
He was of noble east Thuringian stock, the eldest son of Margrave Gunther of Merseburg. In 985 young King Otto III of Germany appointed him to succeed Margrave Rikdag in Meissen, following severe Saxon setbacks against the Slavic Lutici tribes. He was later elected Duke of Thuringia by the magnates of the region, an event which has been taken as evidence of the principle of tribal ducal election. Eckard was high in the favour of the Emperor Otto III, who rewarded him handsomely by converting many of his benefices (fiefs) into proprietas (allods). In Otto's conflict with his rivaling cousin Duke Henry II of Bavaria, Eckard's military responsibilities as holder of the Meissen march consisted primarily of containment of the neighbouring Polish and Bohemian duchies. Duke Boleslaus II of Bohemia had allied with Duke Henry and had taken the occasion to occupy the Albrechtsburg in 984, he nevertheless had to withdraw the next year, after Otto III had prevailed. Margrave Eckard had to restore Thiadric, Bishop of Prague to his see after his expulsion by Boleslaus II of Bohemia.

When in January 1002 Otto III died without issue and the German princes met at Frohse (today part of Schönebeck) to elect a new king, Eckard even aimed at the German crown, because the late emperor's Ottonian relative Henry of Bavaria, son of Duke Henry II, who was the preeminent candidate, met with strong opposition. Eckard was at that time the most obvious Saxon candidate, but the nobles were opposed to him. They only agreed to meet again at the Kaiserpfalz of Werla and to support no candidate before then. The Werla meeting took place in April and Henry, through his cousins, Abbess Sophia I of Gandersheim and Adelheid I of Quedlinburg, the sisters of deceased Otto III, succeeded in having his election confirmed, at least in part by hereditary right. Nevertheless, Eckard received enough support to commandeer the closing banquet of the Werla assembly and dine in state with Duke Bernard I of Saxony and Bishop Arnulf of Halberstadt. He was subsequently honoured as royalty by Bishop Bernward when he arrived at Hildesheim. Within days, however, he had been assassinated by agents of his Saxon opposition in Pöhlde. Among these rivals were Count Henry III of Stade, his brother Udo, and Count Siegfried II of Northeim.

Eckard was initially buried at his family's castle in Kleinjena near Naumburg, but his remains were transferred to the Benedictine monastery of Saint George in Naumburg in 1028. He was remembered by Bishop Thietmar of Merseburg as decus regni, solatium patriae, comes suis, terror inimicis et per omnia perfectissimus. Meissen fell into dispute on his death. King Bolesław I Chrobry of Poland, who had supported Eckard for the throne, laid claim to it as his relative by marriage. Henry, now king, alloted to Bolesław the March of Lusatia (which had been attached to Meissen), but Meissen itself was granted to Gunzelin, Eckard's younger brother.

Eckard left behind his wife Schwanehilde (Suanhild), daughter of Hermann Billung, regent of Saxony. She died on 26 November 1014, having given him seven children, though he was her second husband, she being the widow of Margrave Thietmar, Margrave of Meissen (96383594):

1.Liutgard (d. 1012), married Margrave Werner of the Northern March

2.Herman I, Margrave of Meissen (d. 1038), married Regelinda (122573029), daughter of King Bolesław I Chrobry of Poland (66462184)

3.Eckard II, Margrave of Meissen (d. 24 January 1046), married Uta, sister of Count Esico of Ballenstedt

4.Gunther (d. 1025), Archbishop of Salzburg

5.Eilward (d. 1023), Bishop of Meissen

6.Matilda, married Dietrich II, Margrave of Lower Lusatia

7.Oda (d. after 1018), married King Bolesław I Chrobry of Poland (66462184)