Turkish media pictures earlier showed Sumeyye, 30, wearing an Islamic headscarf, sitting in the front seat of the bridal car.
Erdogan and his wife Emine have four children — eldest son Burak who is rarely seen in public, Bilal and two daughters Esra and Sumeyye.
Prime Minister Ahmet Davutoglu is expected to be Sumeyye’s witness and army chief Hulusi Akar for the groom at the wedding ceremony to be attended by some 6,000 guests, media reports said.
In a surprise move, Davutoglu announced last week he would step down as premier and leader of the ruling Justice and Development Party (AKP) at a congress later this month.
Davutoglu, a heavyweight former foreign minister, is believed to have been forced out of office due to repeated disagreements with Erdogan and that the key quality in the next head of government will be loyalty.
His appearance at the wedding could dismiss claims of a split with the president.
In Istanbul some roads were closed to traffic because of the wedding and additional barriers were put up around the wedding hall in Kucukcekmece on the European side of the city, media reports said.
The groom Bayraktar graduated from Istanbul Technical University’s department of electronic engineering in 2002.
He received masters degrees from the University of Pennyslvania and the Massachusetts Institute of Technology, and his doctorate from the Georgia Institute of Technology in the United States.
He has been working as chief technology officer at a family company Baykar Makinam which manufactures unmanned aerial vehicles. He has taken part in a number of projects on the development of national defence systems.
© 1994-2016 Agence France-Presse