The party system that was operational in Nigeria under the aborted Third Republic was the

Nigeria's aborted Third Republic (1992-1993) operated under a two-party system. General Ibrahim Babangida's military administration created exactly two political parties for the transition programme: the Social Democratic Party (SDP), described as "a little to the left," and the National Republican Convention (NRC), described as "a little to the right."

This was a unique arrangement in Nigerian political history because both parties were created by the military government rather than emerging organically from the political landscape. The government wrote their constitutions, provided their initial funding, built their secretariats, and defined their ideological orientations. All other political associations were banned, ensuring that only these two parties could participate in the transition elections.

The Third Republic is described as "aborted" because the process never reached completion. The presidential election held on 12 June 1993, which was widely believed to have been won by Chief M.K.O. Abiola of the SDP, was annulled by the Babangida administration, effectively killing the transition to civilian rule.

This is distinct from the Second Republic (1979-1983), which operated a multi-party system with five registered parties, and the Fourth Republic (1999-present), which also operates a multi-party system.