President and AK Party Chairman Recep Tayyip Erdogan was named the AK Party's candidate and is supported by the nationalist MHP and the Great Unity Party (BBP).
"Our candidate has always been determined by the people".
Since the abortive putsch, authorities have carried out a sweeping crackdown on alleged supporters of the US -based preacher Fethullah Gülen, whom Ankara blames for the coup attempt, detaining 160,000 people and dismissing almost the same number of civil servants, the United Nations said in March.
Erdogan has served as president since 2014 - Turkey's first popularly elected president.
The AKP and the MHP have also reportedly agreed on the protocol to be implemented under the "People's Alliance".
In a bid to challenge Erdogan and his alliance, the main opposition Republican People's Party (CHP) is set to announce a four-party alliance of its own with the newest Iyi (Good) Party and smaller Democrat and Saadet (Felicity) Parties.
The pro-Kurdish Peoples' Democratic Party (HDP), which is strongly hostile to Erdogan, has named charismatic former leader Selahattin Demirtas as its presidential candidate even though he is now behind bars.
Speculation rose on Thursday that prominent CHP MP Muharrem Ince would be the party's presidential candidate.
A formal announcement by the CHP on its candidate is expected on Friday morning.