Thanasis Nasiakopoulos, of George and Vaia Nasiakopoulos, was born in 1954 in Dilofos, Larissa. He graduated from Dilofos Primary School and continued his education at the 1st high school of Larissa. He is married to Maria Kiafa and has three children, Vaia, George and Katerina.

He was engaged with agriculture for several years. He was then employed by several businesses.

In 1980, his restless spirit led him to establish his first personal business, at the age of 26, promoting and selling agricultural equipment. This was his first success as a businessman. In 1989, he moved his company's headquarters to personally owned facilities, while changing his business subject to car sales. His business, following continuous expansions and development, is still operating successfully, maintaining the same legal form, since 2002.

At the same time, he was also involved with a number of different professional activities, offering a high number of much needed job positions in the greater area, during country-wide financial sanctions and restrictions.

Throughout his professional career, he was also involved with the community. It is widely known that he would always assist and support all sports, cultural, educational and other clubs in the area.

Following the urge and advice by fellow residents and given that his children could ultimately inherit and manage his businesses, Thanasis has made the decision to get more involved with municipal matters. In a spectacularly short period of time, he has managed to unite a large section of the Municipality residents and combine a number of diverse views and perceptions, founding the "New Killeler" party.

He successfully run for Mayor of Killeler Municipality for the first time in May 2014.

He was subsequently re-elected as Mayor, in May 2019 municipal elections.