Sergej was born in Mostar, SR Bosnia and Herzegovina, SFR Yugoslavia to father Tomislav, an actor, and mother Slobodanka, a lawyer.

[1] His father's career made the family move between cities, thus Sergej's early years were spent in Mostar, Užice, Kruševac and Belgrade.

[4] In 1990, Trifunović enrolled in the Belgrade Faculty of Drama Arts; fellow students included Nataša Ninković, Vojin Ćetković and Nebojša Glogovac.

[6] The joint report by European Economic and Social Committee and Civic Initiatives noted that Trifunović and his charity foundation have been targets of a smear campaign and false accusations by pro-government media and members of ruling parties since 2018.

[11][12] On 16 June 2020, Sergej Trifunović published and then deleted the video showing him, along with Srbijanka Turajlić, singing a Chetnik song, which was followed by heavy criticism on social networks from the liberal and leftist public in Serbia.