Dado Ćosić was born in Bosanska Dubica, Bosnia and Herzegovina, on 14 December 1987. He took his master’s degree from the Zagreb University Academy of Dramatic Arts in 2014 and has been the member of the Zagreb Youth Theatre (ZKM) company since 2015.
Shows played at ZKM: Čarobni brijeg (The Magic Mountain, directed by Janusz Kica), Hinkemann (directed by Igor Vuk Torbica), Sherlock Holmes (directed by Krešimir Dolenčić), Velika bilježnica (The Notebook, directed by Edvin Liverić), Alisa u Zemlji čudesa (Alice in Wonderland, directed by Renata Carola Gatica), Črna mati zemla (Black Mother Earth, directed by Dora Ruždjak Podolski), Tit Andronik (Titus Andronicus, directed by Igor Vuk Torbica), Pansion Eden (directed by Árpád Schilling), Huddersfield (directed by Rene Medvešek), Eichmann u Jeruzalemu (Eichmann in Jerusalem, directed by Jernej Lorenci), Monovid-19 (directed by Anica Tomić), Cement (directed by Sebastijan Horvat), H.E.J.T.E.R.I (H.A.T.E.R.S., directed by Judita Gamulin), Kamen (The Stone, Patrik Lazić), Ja sam ona koja nisam (I Am Who I’m Not, directed by Paolo Magelli), and Braća Karamazovi (The Brothers Karamazov, directed by Oliver Frljić)
Dado has also performed at other theatres and events, including the Dubrovnik Summer Festival, Ulysses Theatre, and &TD Theatre and worked with directors such as Andraš Urban, Lenka Udovički, and Dario Harjaček. As a film actor he worked with Dalibor Matanić, Predrag Ličina, Vlatka Vorkapić, Andrej Korovljev, Ivona Juka, Jasna Nanut, and others.
For his performances he received a number of awards, including the Golden Arena for the supporting role in the film Zvizdan (The High Sun, 2015), the 2012 Croatian Actor Award in the category of the best actor in plays for children and adolescents for his role in the show Ružičasta sanjarica (The Pink Dream Interpretation Book, Theatre Mala scena), for which he also won the Marul Award as the best actor at the Mali Marul Festival that same year. For the best role in Huddersfield he won the the 2019 Veljko Maričić Award at the International Small Scene Theatre Festival Rijeka and the Mediterranean Award. He also won the Ardalion Award for the best male role in Eichmann u Jeruzalemu (Eichmann in Jerusalem) at the 27th Yugoslav Theatre Festival in Užice, Serbia.