The 29-year-old drag singer - who was catapulted to fame after winning the Eurovision Song Contest in 2014 as the entrant for Austria - took to Instagram to tell the fans following on the social media site that he is living with disease.
Conchita - whose real name is Thomas Neuwirth - wrote in Austrian on the photo sharing platform: "Today the day has come to liberate me from the sword of Damocles for the rest of my life: I have been hiv-positive for many years. this is actually irrelevant to the public, but an ex-boyfriend threatened me to go public with this private information, and I will not give anyone the right to frighten me and influence my life in the future.
"Since I received the diagnosis, I have received medical treatment and for many years I've been under the detection limit, so am not able to pass on the virus. [sic]"
The 'Rise Like A Phoenix' singer had chosen not to speak out about the diagnosis in order to protect family members from public scrutiny.
Conchita added: "Secondly, it is information that I believe is mainly relevant to those people with whom sexual contact is an option. Coming out is better than being outed by a third party. I hope to build up courage and take another step against the stigmatisation of people who have become infected by hiv, either through their own behaviour or through no fault of their own. To my fans: the information about my hiv status may be new to you - my status is not! I'm well, and I'm stronger, more motivated and liberated than ever. Thank you for your support! [sic]"
Since sharing the news, Conchita has been flooded with messages of support from fans on social media.