Known for her frequently changing hair colour, Kelly (nickname Kelly O and Kel) was born after an 18 hour intensive labour in London, England.
Her parents are Ozzy and Sharon Osbourne and she is the sister of Jack and Aimee Osbourne. Kelly is half-sister to Louis Osbourne and Jessica Mayfair.
Kelly's uncle is David Arden and her grandfather is Don Arden.
Kelly dropped out of school in the 10th Grade
Her ex-boyfriend, Bert McCracken, is the lead singer of the band, The Used.
She was dropped by her record label, Epic in 2003.