Formed in February 2013, the party is the result of a merger of Nigeria's three biggest opposition parties – the Action Congress of Nigeria (ACN), the Congress for Progressive Change (CPC), the All Nigeria Peoples Party (ANPP), a faction of the All Progressives Grand Alliance (APGA) and the new PDP - a faction of then ruling People's Democratic Party.[13][14][15] The resolution was signed by Tom Ikimi, who represented the ACN; Senator Annie Okonkwo on behalf of the APGA; Ibrahim Shekarau, the Chairman of ANPP's Merger Committee; and Garba Shehu, the Chairman of CPC's Merger Committee.[16] Ironically, less than 2 years before the party's historic victory in the 2015 elections, Messrs. Annie Okonkwo, Tom Ikimi and Ibrahim Shekarau resigned from the party and joined the PDP.[17][18][19]

The party received approval from the nation's Independent National Electoral Commission (INEC) on 31 July 2013 to become a political party and subsequently withdrew the operating licenses of the three parties that merged (the ACN, CPC and ANPP). In March 2013, it was reported that two other associations – African Peoples Congress and All Patriotic Citizens – also applied for INEC registration, adopting APC as an acronym as well, reportedly "a development interpreted to be a move to thwart the successful coalition of the opposition parties, ahead of the 2015 general elections."[20] It was reported in April 2013 that the party was considering changing their name to the All Progressive Congress of Nigeria (APCN) to avoid further complications.[21]

In November 2013, five serving Governors from the governing PDP defected to the APC, as well as 49 legislators who joined the ranks of 137 legislators in the APC as a result of the prior merger of the smaller opposition parties.[22][23][24] This initially gave the APC a slim majority of 186 legislators in the Lower House out of a total of 360 legislators; however, subsequent political wrangling and pressure from political factions and interests outside the National Assembly of Nigeria, gave the party only 37 additional legislators thus giving the APC a nominal majority of 172 out of 360 Legislators, as opposed to the PDP's 171 (though some smaller PDP-allied parties hold the balance of the other seats.[25] This was further confirmed when the party seated 179 members on 15 January 2015 when the House resumed after a long recess to finally affirm its majority.[26] The governors who defected to the APC were Rotimi Amaechi of Rivers State, Abdulfatah Ahmed of Kwara State, Rabiu Kwankwaso of Kano State, Murtala Nyako of Adamawa State and Aliyu Wamakko of Sokoto State. It had been previously reported that Governors Mu'azu Babangida Aliyu of Niger State and Sule Lamido of Jigawa State were set to defect from the People's Democratic Party to the APC; however, both ended up remaining with the People's Democratic Party. In the 2015 elections, Mu'azu Babangida Aliyu ran as a senatorial nominee of the People's Democratic Party for the Niger State east senatorial district, losing in a landslide to the APC's David Umaru.[27]

On 12–13 December 2014, the APC was admitted as a consultative member into the Socialist International.[28]

On 4 July 2018, important members who were earlier identified as nPDP caved again out from APC to formed "Reformed APC" this is done ahead of 2019 general election. The formation of the R-APC made the opposition, the PDP the majority in the Senate.[29]

Prior to the formation of the APC and its victory in the 2015 elections, Muhammadu Buhari had previously contested (and subsequently lost) the Nigerian presidential elections of 2003 and 2007 as the presidential nominee of the All Nigeria Peoples Party (ANPP) and the 2011 Nigerian presidential election as the presidential nominee of the Congress for Progressive Change (CPC).

Where is Tinubu our national leader?