The 23-year-old singer has slammed the CW television show for branding the superhero action adventure programme with a misleading title that might make people "feel bad".
Speaking to Variety magazine, the 'Wrecking Ball' hitmaker said: "I think people will have to realise they're looking really dated. For example, there's a show called 'Supergirl'. I think having a show with a gender attached to it is weird. One, it's a woman on that f***ing billboard -- it's not a little girl. Two, what if you're a little boy who wants to be a girl so bad that this makes you feel bad? I think having a title like "Supergirl" doesn't give the power that people think it does."
And the star admits she only realised that she could use her voice to help change the world after her controversial 2013 VMAs performance - which saw her dance provocatively with Robin Thicke - went viral.
She said: "In 2013, when I did the VMAs, it became the biggest story in the world. I never expected that to happen. I just did my own thing. I went out there dressed as a teddy bear, danced with teddy bears, never thought about the world thinking that was going to be a bad thing.
"It was making me feel like I was living a dumb life -- like I should just pick another job. I didn't understand my power at that point. People listen because of who I am, so instead of being embarrassed, I should say: 'F**k yeah, I got the microphone.'"
But for the family of the 'We Can't Stop' singer - who is currently on the judging panel for American talent competition 'The Voice' - it isn't until a fan tells them how Miley has changed their life that they really understand what she stands for.
She said: "On 'The Voice', this young girl started crying when she left, because I'm the reason she came out. My mom started crying. She was like, 'I'm so sorry about the way I was when you were that age and coming out.' She never understood me until she saw that girl who couldn't be herself. It was very cool."