After studying at the Vienna University of Economics and Business Administration in 1995, Dejan Turk began his career at McDonald’s Slovenia as a restaurant manager, leaving the same company as the executive director of a restaurant chain in Slovenia and Croatia.

He joined A1 Telekom Austria Group in August 2004 as Marketing and Sales Manager at Si.mobil (now A1 Slovenia). He was the President of the Management Board of Si.mobil from 2007 to 2014, when he transferred to Vip mobile (now A1 Serbia) to the position of CEO. Since 2015, he has been taking over the position of director / CEO / CMO of the new organizational unit "Serbia and Slovenia" within the A1 Telekom Austria Group. Dejan has been the General Manager of A1 Serbia and A1 Slovenia since July 1, 2015.

Turk is the winner of many prestigious awards for six years of successful management of Si.mobil (Excel 2009, Manager of the Year 2009, Award for the greatest achievements in business and the economy of Slovenia in 2013). He is the President of the Forum for Responsible Business, the Vice President of the E-Government Council of NALED and the Council of Foreign Investors (FIC) and a member of the Board of the Serbian Association of Managers.

He is a member of the Supervisory Board of A1 Telekom Austria AG, a member of the A1 Telekom Austria Group, as well as the Management Board of NLB Bank a.d. Belgrade

In Serbia, he was awarded the "Captain Miša Anastasijević" award for business excellence, leadership and socially responsible business in 2015, while a year later he was named Business Ambassador of the Leader of Change by the American Chamber of Commerce in Serbia (AmCham). At the end of 2018, the Serbian Association of Managers awarded him the prestigious "Manager of the Year" award.