Batbayan
{{Infobox monarch | name = Bat Bayan
| title = Ruler of Bulgars
| image =
| reign = 667 to 690 CE
| predecessor = Kubrat
| successor =
| spouse =
| royal house =
| father = Kubrat
| mother =
| birth_date =
| birth_place =
| death_date =
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|}}
Batbayan ruled the Khazarian Bulgars from 667 to 690 CE.
{{cite book
|last1 = Dinkov
|first1 = Stoyan
|editor-last1 = Radev
|editor-first1 = Radoslav
|year = 2018
|title = Османо – Римска империя, българи и тюрки
|url = https://books.google.com/books?id=XblQDwAAQBAJ
|language = bg
|edition = 2
|publication-place = Sofia
|publisher = Uncorp.org
|access-date = 21 August 2023
|quote = Каганите стават балтавари: Бат-Баян Дуло (667–690), Бу-Тимер (690–700), Сулоби (700–727), [...].
}}
Boris Zhivkov, Khazaria in the Ninth and Tenth Centuries, East Central and Eastern Europe in the Middle Ages, 450-1450, BRILL, 2015, {{ISBN|9004294481}}, p. 138 & 228-229. Theophanes and Nicephorus record his rule after the Khazars defeated the Bulgars and Old Great Bulgaria disintegrated in 668 CE.Carl Waldman, Catherine Mason, Encyclopedia of European Peoples, Facts on File library of world history, Infobase Publishing, 2006, {{ISBN|1438129181}}. pp. 106-197.
There is a scholarly theory that he may have been the same person as BezmerBoris Zhivkov, Khazaria in the Ninth and Tenth Centuries, East Central and Eastern Europe in the Middle Ages, 450-1450, BRILL, 2015, {{ISBN|9004294481}}, p. 228. of the Nominalia of the Bulgarian khans who may have been also the first son of Kubrat.Florin Curta, Roman Kovalev as ed., "'The' Other Europe in the Middle Ages: Avars, Bulgars, Khazars and Cumans", Volume 2 of East Central and Eastern Europe in the Middle Ages, 450 - 1450, BRILL, 2008, {{ISBN|9004163891}}, p. 152. He was a member of the Dulo clan, who after Kubrat's death in the mid-7th century ruled Old Great Bulgaria, but his rule lasted only three years.Vasil Gyuzelev, The Proto-Bulgarians: Pre-history of Asparouhian Bulgaria, Sofia Press, 1979, p. 29. Kevin Alan Brook calls him Bayan.Kevin Alan Brook, [https://books.google.com/books?id=MqhFDwAAQBAJ The Jews of Khazaria], Edition 3, Rowman & Littlefield, 2018, {{ISBN|1538103435}}, p. 15. Batbayan would subsequently have ruled the Bulgars as a subject of the Khazar Khagan.