Conrad of Krosigk (c. 1162[1] – 21 June 1225) was a German prelate, crusader and monk. He served as the bishop of Halberstadt from 1201 until 1208 and took part in the Fourth Crusade in 1202–1204. He resigned his see to become a Cistercian monk at Sittichenbach Abbey. In his retirement, he undertook frequent Papal missions.
Born to a minor noble family, Conrad rose through the ranks of the diocese of Halberstadt. By 1193 he was chief provost, shouldering major responsibility during Bishop Gardolf's absence on the Crusade of 1197–1198. He supported Duke Philip of Swabia over Count Otto of Poitou in the German succession war that began in 1198. For this reason, he was excommunicated shortly after his election as bishop and joined the Fourth Crusade. He was with the army at the sack of Constantinople. Afterwards he fulfilled his vow to go to the Holy Land and exercised episcopal authority in the see of Tyre during the archbishop's six-month absence. He later served as vicar of the see of Naumburg for over a year in 1217–1218.
Upon his return to Europe after the crusade, Conrad made peace with Otto. He resigned his bishopric and took monastic vows against the orders of Pope Innocent III. Nonetheless, he received Papal commissions fifteen times in the last fourteen years of his life. In 1209, he commissioned the extension of the Deeds of the Bishops of Halberstadt down to the end of his own pontificate, including an important account of the Fourth Crusade based in part on his eyewitness testimony.