Nikola Vuljanić was born in Karlovac, and graduated at the University of Zagreb with an MA in philology.
After the first deputy term, he left HNS and joined Croatian Labour Party (HL).
Vuljanić was a member of the parliamentary group of the Croatian People's Party-Liberal Democrats (HNS).
Serving as non-attached member few days, on 18 April 2012, Vuljanić finally joined the Group of the Progressive Alliance of Socialists and Democrats in the European Parliament (S&D).
On 1 July 2013, after Croatia joins the European Union, Vuljanić was sworn in as full MEP.