Bulcsú (Hungarian pronunciation: [ˈbult͡ʃuː]; or Vérbulcsú; Latin: Bultzus, Greek: Βουλοσουδης "Boulosoudes" and Βουλτζους "Boultzous", Arabic: Wulǧūdī; c. 910 – 15 August 955) was a Hungarian chieftain and military leader in the 10th century. He held the title of harka (Greek: karchas). Despite not being a member of the ruling Árpád dynasty, he was one of the most important figures of the Hungarian invasions of Europe. He led military campaigns in directions to the northwest, west and south either in the period 930–950s.
In 948, Bulcsú visited the court of Byzantine Emperor Constantine VII, where he was received with a great pomp. Bulcsú adopted Christianity, the emperor became his godfather. He was a "guest friend of the emperor" and was awarded the title of "Roman patrician" (or patrikios).