Burchard I (died 5 or 23 November 911) was the duke of Swabia from 909 to his death and margrave of Rhaetia, as well as count in the Thurgau and Baar. Born between 855 and 860, he was the son of Adalbert II, count in the Thurgau. He himself married Liutgard of Saxony.

By 900, Burchard was already the most powerful man in Swabia. In 904, he was the administrator of the lands of the abbey of Lorsch in Swabia. He succeeded, around 909, Ruadulf (a Welf) as dux or marchio (duke of margrave) of Raetia Secunda (the borderlands of Rhaetia). Burchard entered into a conflict with the Count Palatine Erchanger and Bishop Solomon III of Constance, who were loyal to King Conrad I. Burchard was captured and charged with high treason. He was found guilty by the tribal council and executed, along with his brother, Adalbert III of Thurgau. His son, Burchard II, and daughter-in-law, Regelinda, left for Italy, either exiled or taking refuge. Their Rhaetian estates were lost, though later recovered. Burchard I's second son, Odalric, had already died young.

His daughter Dietpirch of Swabia (also known as Theoberga) married Hupald, Count of Dillingen (d. 909). Their children included Ulrich of Augsburg.

The state of Swabia relative to the other stem duchies was highly disorganized at the time of Burchard I and he was never duke in the sense of the later dukes. He is usually called such only to distinguish him as the most powerful man in the duchy and the forerunner of the later dukes: the first being Erchanger, proclaimed duke by the nobility, but not the king, in 915.