Babban Banki, reserve bank, or monetary authority babbar hukumar gwamnati ce, wadda take kula da lura da harkokin kudaden kasa, kamar Kudi, Samarda Kudi, Riba. Babban banki kuma na lura da harkokin tsarin Bankunan Kasuwanci dake a kasashen da bankunan suke. Babban banki ba kamar bankunan kasuwanci bane, domin ita take da iko kawai wurin kara yawan kudaden da kasa ke amfani dasu, da kuma ita take buga kudaden da kasa ke amfani dasu, wanda ke zama a matsayin abun amfani da aka yarda dashi a harkokin cinikayya. Cite web |url= http://www.bankofcanada.ca/2013/11/5-and-10-bank-note-issue-2/%7Ctitle=$5 and $10 Bank Note Issue|author=Bank of Canada|publisher=|accessdate=7 November 2013