Kogin kongo (Kongo: Nzâdi Kôngo, Faransanci: Kongo fleuve, Fotigal: Rio Congo), wanda a da ake kira da Kogin Zaire, shine kogi na biyu mafi tsayi a Afirka, gajere kaɗan ne kawai fiye da Kogin Nilu, kazalika da kogi na biyu mafi girma a duniya ta hanyar fitarwa, suna bin Amazon kawai. Har ila yau, shine mafi zurfin rafin da aka yi rikodin a duniya, tare da zurfin zurfin da ya zarce 220 m (720 ft). Tsarin Kogin Congo-Lualaba-Chambeshi yana da tsawon kilomita 4,700 (mi mi 2,920), wanda ya sa ya zama kogi mafi tsayi na tara a duniya. Chambeshi yanki ne na Kogin Lualaba, kuma Lualaba shine sunan Kogin Kongo wanda yake hawan Boyoma Falls, wanda yakai 1,800 km (1,120 mi). An auna shi tare da Lualaba, babban harajin, Kogin Congo yana da tsawon tsawon 4,370 km (2,715 mi). Babbar kogi ce kaɗai ta ƙetare mashigar teku sau biyu. Kogin Kongo yana da yanki kusan kusan 4,000,000 km2 (1,500,000 sq mi), ko kuma 13% na duk ƙasar Afirka.