Ambassador Vishnu Prakash unfurled the tricolour to the cheers of hundreds of individuals, including members of the embassy and their families, who assembled for the occasion.
It was followed by the rendering of the national anthem and a brief cultural programme put up by Korean students of the Indian Cultural Centre and members of the community.
Vishnu Prakash read out excerpts of Indian President Pranab Mukherjee's message to the nation.
The Republic Day celebrations began as early as Jan 23, with a reception hosted by the ambassador at Hotel Hilton Millennium here.
The event was attended by Jeong Kab-yoon, member of the National Assembly and chairman of India-Korea Parliamentary Friendship Association, and Shim Yoon-joe, member of the National Assembly.
Over 400 guests, including Korean officials, industrialists, cultural and academic personalities, members of media, Indian companies in Korea, diplomatic and Indian communities, joined the festivities.
Referring to India as "a friend and well-wisher of Korea", Shim had expressed his conviction that President Park Geun-hye's recent state visit to India would not only enhance bilateral ties, but also contribute to the prosperity of the regions.
Shim highlighted India's role as a factor of peace and stability in the world, and the growing support for India's candidature as a permanent member of the United Nations Security Council.
Various cultural programmes, including the classical Kathak dance form, tabla recitals, a yoga presentation and folk dances from the Indian states of Gujarat and Rajasthan, were organised at the event.