Valentin Hajdinjak was born in Ljubljana on 6 December 1973. He graduated from the Faculty of Economics at the University of Ljubljana, International Trade programme. As a student (1992–1994) he worked part-time at RTV Slovenia and occasionally as a tourist guide. Between 1994 and 2000 he worked as press officer for the Slovenian Christian Democrats. In 2000 he was press officer in the Office of the Prime Minister Dr Andrej Bajuk.  At the beginning of 2001 he began working as the editor of the news programme of Radio Antena, and from March 2002 he worked as press officer at the Ministry of Agriculture, Forestry and Food, where he later took over as Head of the Public Relations and Promotion Service. In December 2004 he was appointed Head of the Minister's Office at the Ministry of Labour, Family and Social Affairs.

Between 1993 and 1994 he was appointed Member of the Advisory Council of the Foreign Minister of the Republic of Slovenia, in 1995 and 1996 he worked as Member of the Governing Board and the Advisory Committee of the European Youth Centres and European Youth Foundation of the Council of Europe in Strasbourg. In 2004 he was also Member of the Administrative Board of the Slovenian Tourist Board.

Valentin Hajdinjak has always been actively involved in work with young people, in Slovenia, in the EU, and elsewhere in the world.

He is proficient in English, and has a working knowledge of German and French.