Laura Moon, from Whinmoor, is one of a tiny percentage of the population with four of the organs naturally.
She was inspired to look into donation after reading a YEP story about three-year-old Luke Heppenstall, who urgently needs a new kidney.
Laura, 18, said: "I'm not exactly sure how donations work but I know that I have four kidneys and would like to help somebody like Luke if possible."
The kind-hearted teenager is now investigating whether she could become a live donor, though she would not be allowed to choose the recipient.
She was shocked to be told she had four kidneys during a routine ultrasound scan at Seacroft Hospital. Laura had the scan to investigate stomach pains when it picked up her unusual anatomy.
"The guy just said 'you have got four kidneys'," she said.
"He measured them and I have two which are 14cm and two which are 9cm.
"Then he also asked if I would mind if he took some photos to show to university students."
After the scan Laura told her mum Catherine and dad Austin - and was even more surprised that on the same day her auntie Dawn Fry had learned she had three kidneys too.
The pair aren't related by blood, though having one double kidney - known as a duplex - is less uncommon than having four.
Laura hadn't realised how rare she was until she contacted the YEP about the possibility of donating.
"I think if I've got four, I don't need all four," added Laura, who is about to start a job as a customer service advisor.
"Why not donate if there's someone else in need."
Transplant surgeon Niaz Ahmad, from Leeds Teaching Hospitals NHS Trust, said parts of the kidney system could be duplicated but he had never seen anyone with four full kidney systems.
"To have completely duplex kidneys on both sides is extremely rare," he added.
Laura's inspiration, Luke Heppenstall, from Morley, Leeds, had both kidneys removed because of cancer and is on dialysis to keep him alive.
But that cannot go on forever and he desperately needs a transplant. He is on the waiting list but needs a small kidney because of his size.
John Oliver, from UK Transplant, said live donors giving kidneys to strangers - known as Altruistic Non-Directed Donation - was now allowed, though recipients must remain anonymous beforehand.
Those interested can get more information via their GP or the Renal Unit at St James's Hospital.
Only if the donor is a close family member or friend can they donate to a specific person.
To sign up to the Organ Donor Register, go to www.uktransplant.org.uk or ring 0845 60 60 400.