Theodore Kalantonis was graduated with a degree in chemical engineering from the National Technical University of Athens and holds a Master in Business Administration from Manchester Business School.

From 2000 to 2013, he served as Chief Executive Officer and as head of household lending of Eurobank Cards S.A.. After working for more than one year as Executive General Manager responsible for the retail banking for performing & non-performing loans, the digital banking and the international retail at Alpha Bank S.A., he joined Eurobank Ergasias S.A. as Head of Retail Banking. From 2016 to 2020, he worked as deputy Chief Executive Officer and executive member of the Board of Directors at Eurobank Ergasias S.A..

He joined the doValue Group in 2020 as Executive Chairman of the Board of Directors of doValue Greece, and he holds also the role of Region Manager Greece e Cyprus. Currently he holds the role of Chief of Group NPE & Real Estate.