Erdogan rejoined the ruling Justice and Development Party (AKP) on May 2 after the public approved changes to create an executive presidency on April 16.
Under the old constitution, the head of state had to sever ties with their political party and Erdogan left as AKP chairman in August 2014 after his election as president.
Rejoining the AKP was the first major change permitted after the vote, allowing the president to be affiliated with a political party almost immediately.
However, as leader Erdogan can decide the party's direction.
Also Read
Current party leader and Prime Minister Binali Yildirim will be given a newly-created role of "vice chairman", AKP deputy chairman Hayati Yazici said on Saturday.
Erdogan led the party for three terms during his premiership between 2003 and 2014, after he co-founded it in 2001.
The father-of-four affectionately describes the most effective Islamic rooted political force in the history of modern Turkey as his fifth child.
With Erdogan as party leader, all eyes will be on the cabinet, with Hurriyet daily speculating at the weekend that eight to 10 ministers could be reshuffled.
Nearly 1,500 delegates will vote to decide the new party leader, state-run news agency Anadolu reported, in an election where there is only one candidate: Erdogan.
If chosen, it will be the first time the president will be both party chairman and head of state since the end of the presidency in 1950 of Ismet Inonu, the successor and right- hand-man of Mustafa Kemal Ataturk, Turkey's modern founder.
A special congress slogan reads "a new breakthrough period: democracy, transformation, reform" hinting at the expected restructuring of the government as well as changes to the party's executive in the coming weeks and months.
Erdogan told party officials "the new period means a new action plan" without giving details, Hurriyet reported on Saturday.
Up to 60,000 participants from across Turkey are expected to descend on Ankara for the congress in the stadium in the city centre, Anadolu reported.
Disclaimer: No Business Standard Journalist was involved in creation of this content