Samantha Devine, a 13-year-old Catholic pupil at the non-denominational mixed Robert Napier School in Gillingham, Kent, was given the cross as a Christmas present but was told by the school that it contravened its health and safety policy.
Samantha argued: "Everyone says they believe in God by going to church, but I believe in him my own way.
"If I've got a problem, I always get it [the crucifix] and talk to it, and I feel that helps me," she said, according to the BBC.
Her father dismissed the request from the school as political correctness gone mad, while Samantha said she should be allowed to wear a symbol of her Christian faith.
Danny Devine, 30, said: "It's just political correctness gone absolutely mad. It's a harmless crucifix and she wears it as a symbol of her religion.
"I'm sure the school wouldn't dare ask anyone of another religion to remove a symbol representing their faiths or beliefs. This has upset the entire family."
Deputy head teacher Paul Jackson defended the school's stance. He said: "The school has a policy of no jewellery to be worn by any students in years seven to 10. All parents and students are aware of this.
"In this particular instance, the student, and parent, were informed that the wearing of the chain was a health and safety hazard, but that we would allow a lapel badge to be worn.
"The only exception to our uniform rule we would consider making is if the jewellery were an essential requirement of a particular religion. We have no reason to believe this to be the case in this instance."
He added: "We haven't told her she can't wear the crucifix... she could wear a lapel badge to show her commitment to her religion," he said.
This position has won the backing of devout Christian Kent MP Ann Widdecombe, who said this was a "reasonable compromise".
"The school has said she can wear her symbol ... so it's not actually preventing her from displaying a cross or a crucifix," said Ms Widdecombe.
The human rights group Liberty, meanwhile, questioned whether there were any real health and safety implications over pupils wearing items of religious jewellery during standard lessons.
The latest row comes not long after BA check-in worker Nadia Eweida took the airline to court to win the right to wear her crucifix necklace to work.
British Airways withdrew its controversial ban on workers wearing a visible cross, following widespread condemnation and criticism from within the UK and around the globe.
