Janko Sinadinovic was born in Belgrade where he begun his studies of solo singing.
He continued his professional education in Opera Academy in Osimo, Italy where he studied with Raina Kabaivanska.
In 1995 he begun his career as a singer and in 1997 he became the soloist of the Opera of the National Theatre in Belgrade.
From 2006. he is the principal opera artist of the National Theatre where he sang many leading  tenor roles among which are Ismail - "Nabucco", Lord Percy - "Anna Bolena", Alfredo Germont - "La Traviata", Cavaradossi - "Tosca", Don Jose - "Karmen", F.B. Pinkerton - "Madama Butterfly", Dr Faust - "Faust", Riccardo - "Un ballo in maschera", Werther - "Werther", Turiddu - "Cavaleria rusticana, Beg Pintorovic - "Hasanaginica", Luigi - “Il tabarro”, Maurizio - “Adriana Lecouvrer”, Manrico - “Il trovatore”, Radames – “Aida”, Erik - “Der fliegende Hollander”, Otello - “Otello”.
Since 1999 he participated in operas: "The rape of Lucretia" B.Britten, "Two widows" B.Smetana "Die Kluge" K.Orf and “Pagiliacci” R. Leoncavallo in the Chambre Opera Madlenijanum in Belgrade.
He also participated at concerts and opera performances in Serbia and abroad - France, Italy, Austria, Japan, Slovenia, FYR Macedonia, Cyprus, Romania.
Awards:
- The National Theatre Annual Award for the roles of Don Hose in „Karmen“and Manriko in „Il trovatore“ in 2012.
- The National Theatre Public Praise for the artistic achievements in the National Theatre in 2015;
- The Golden Badge of the Cultural Educational Association of Serbia for the contribution to the cultural development in Serbia in 2016.

He is the acting Opera director from the Septembar 1 st, 2016.