The socialite – whose father is Bob Geldof – was spotted in Hollywood on Tuesday (29.06.10) buying a ring for her new piercing in her left nostril.
Peaches – who has several tattoos - stopped at a tattoo parlour on Hollywood Boulevard to get the jewellery to finish off her grunge-inspired look.
A source said: "Peaches is really trying to make the grungy rock chick her own. The nose ring really finishes it off, although I'm sure it will be sore for a few days."
Peaches, 21, has moved to Los Angeles to be near her film director boyfriend Eli Roth, 38, but since she settled Stateside she has piled on the pounds.
The British star has previously claimed she doesn't dress for men and enjoys looking "weird".
She said: "It's obvious I'm not dressing for men. I don't want to be sexy, I'm, like, covered in tattoos. I have piercings. I'm just grungy and weird and not what is socially accepted as being beautiful, and I think that's cool.
"I think anti-beauty is amazing. I don't want to dress for men, I think it's almost like a feminist thing."