He was born in 1950 in Edirne. Sedefçi who completed his primary and secondary education in Edirne, graduated from Sakarya State Architecture and Engineering Faculty, Civil Engineering Department in 1976.
Sedefçi, selected as Mayor of Edirne in the local elections held in 1989, continued his task by being selected for the second time in 1994 elections. In local elections held on March 30, 2004, Hamdi Sedefçi was elected as Mayor of Edirne from CHP (Republican People’s Party) for the second time and third time in 2009 local elections.
Sedefçi, carrying out the mission of mayor of Edirne for the longest time, has started lots of work in order to develop Kırkpınar Oil Wrestling in his mayoral term.
EDEN Project, prepared for the international promotion of Kırkpınar Oil Wrestling and the studies about the UNESCO’s Intangible Cultural Heritage List have been come true in his mayoral term.