Brasilia babban birnin tarayya ne na Brazil kuma wurin zama na gwamnatin Tarayyar Brazil. Babban birnin yana cikin yankin Midwest na ƙasar, tare da yankin yanki da ake kira Central Plateau. Dangane da kiyasin Cibiyar Nazarin Geography da Kididdiga ta Brazil (IBGE) na 2021, yawanta ya kasance 3,094.325 da 4,284.676 a cikin babban birni, wanda ya mai da shi birni na uku mafi yawan jama'a a cikin ƙasar. Ba za a iya raba Gundumar Tarayya zuwa gundumomi ba, bisa ga Tsarin Mulkin Tarayya na 1988. Duk da haka, don dalilai masu amfani, Brasília ana ɗaukarsa a matsayin birni. Brasilia kuma ita ce ta biyar mafi yawan yawan garin a Brazil. Babban birnin Brazil shine birni mafi girma a duniya da aka gina a karni na 20. Garin yana da mafi girman GDP ga kowane mutum dangane da manyan birane, na huɗu mafi girma a tsakanin manyan biranen Latin Amurka kuma kusan sau uku sama da matsakaicin kudin shiga na Brazil. A matsayinta na babban birnin ƙasa, Brasília gida ce ga hedikwatar rassa uku na reshen zartarwa na jamhuriya, reshen majalisar dokoki da reshen shari'a da ofisoshin jakadancin ƙasashen waje 127.