Standing at 1.86 m (6 ft 1 in), he played in the point guard position for Lovćen, Budućnost, Profikolor, FMP Železnik, and NIS Vojvodina.

In April 2013, following the departure of Vlada Vukoičić, he became the head coach of the Serbian team Crvena zvezda.

[2] On 2 April 2018, Radonjić was named the head coach of the German team Bayern Munich, after dismissal of Aleksandar Đorđević.

[7][8][9] On 14 February 2021, Radonjić won his fourth Serbian Cup title following a 73–60 win over Mega Soccerbet in the Final.

[12] After poor performance, results and failing to advance in Euroleague play-offs for third year in row, on 21 February 2023 he was fired from Panathinaikos.

[14] Dejan Radonjic's team Bahçeşehir Koleji took the second place of 2023-24 FIBA Europe Cup trophy against Chemnitz Niners in the final.