Kim Petras was born in Cologne, North Rhine-Westphalia, Germany. While she was assigned male at birth, her parents said that from the age of two, Petras knew she was a girl.
In 2006, Petras, then aged 13, appeared on a German television current affairs show in which she discussed her medical gender transition. At age 14, Petras appeared in a documentary and a talk show,in a push to get permission for early sex reassignment surgery at age 16, before the minimum age of 18 in Germany. These appearances resulted in international media coverage of her transition, touting her as the "world's youngest transsexual".
In September 2007, she was a model for a German chain of hair salons. Petras was evaluated by the head of the psychiatric unit at Frankfurt Hospital, Dr Bernd Meyenburg, and approved for gender confirmation surgery at 16 years old; Petras announced, in November 2008, that the surgery was completed. The Daily Telegraph claimed Petras was the youngest person in the world to have had that surgery at the time. About her surgery, she stated "I was asked if I feel like a woman now – but the truth is I have always felt like a woman – I just ended up in the wrong body".
In an interview with BuzzFeed, Petras stated that the first song she ever wrote was "about this dude in second grade who didn't like me back