Erdoğan left a star-and-crescent wreath of red and white carnations on Atatürk's tomb, and he observed a moment of silence with other attendees before the playing of the Turkish national anthem.
The president wrote in the mausoleum's memorial book: "We are working hard to make our Republic stand forever."
He added that the historical day would be crowned with the opening of the production facility for Türkiye's first domestic electric car, TOGG.
"Regardless of the obstacles put in front of us, we are resolutely continuing our struggle to make the current century 'The Century of Türkiye,' and to realize our nation's dreams," Erdoğan said.
Erdoğan will later host a Republic Day reception at the presidential complex.
The Turkish War of Independence started with Atatürk's landing on the city of Samsun on the Black Sea coast in 1919.
Anatolia's liberation from occupation opened a new chapter in Turkish history as the new country was recognized under the Treaty of Lausanne in 1923.
On Oct. 29, 1923, Atatürk officially declared the name of the nation and proclaimed the country's status as a republic.
A vote then took place in Türkiye's parliament, the Grand National Assembly, and Atatürk was unanimously elected the first president of the Republic of Türkiye.
Since then, Türkiye has celebrated Republic Day every year on Oct. 29.
