Erdoğan last visited the CHP 18 years ago during his tenure as Prime Minister, when he attended the opening of the new CHP building and met with then-Chair Deniz Baykal.
Erdoğan was accompanied by ruling Justice and Development Party (AKP) Deputy Chair Mustafa Elitaş and they were welcomed by Özel and lawmaker Namık Tan.
The two leaders posed while shaking hands and greeted journalists as they entered the headquarters.
Shortly before Erdoğan's arrival, the flag with the presidential seal was hoisted at the CHP headquarters.