Frederick I (c. 912 – 18 May 978) was the count of Bar and duke of Upper Lorraine. He was a son of Wigeric, count of Bidgau, also count palatine of Lorraine, and Cunigunda, and thus a sixth generation descendant of Charlemagne.
In 954, he married Beatrice, daughter of Hugh the Great, count of Paris, and Hedwige of Saxony. He received in dowry the revenues of the abbey of Saint-Denis in Lorraine. He constructed a fortress at Fains, on the frontier between France and Germany, and exchanged fiefs with the bishop of Toul. Thus, he created his own feudal domain, the county of Bar. So he became the founder of the House of Bar or the House of Ardennes-Bar, a cadet branch of the House of Ardennes.
The duchy of Lorraine was at that time governed by the archbishop of Cologne, Bruno, who was called the archduke on account of his dual title. In 959, he, in concert with his brother, the Emperor Otto I, divided the duchy, appointing as margraves (or vice-dukes) one Godfrey in Lower Lorraine and Frederick in Upper Lorraine. After Bruno's death, in 977, Frederick and Godfrey were styling themselves dukes.