1250 GMT June 20, 2019
Lady Lumley's School in Pickering, North Yorkshire, England, previously told pupils it would ban all festive activities, BBC reported.
RE (religious education) teacher Chris Paul said "an avalanche of commercialization" had robbed the season of its meaning.
But after hundreds of emails and letters "making a strong case" for jingling the bells and bringing back the baubles, the school relented.
Paul had challenged pupils to consider the true meaning of Christmas and come up with answers to persuade her to change her mind.
Since throwing down the challenge, the school said it had received more than 500 emails and letters.
Head teacher Richard Bramley said, "Those students who really thought about the situation and challenged the decision appropriately created the change and brought back Christmas.
"I hope they and everyone else has a good Christmas."
He said the challenge was to make students consider the way in which society celebrates Christmas and think about the social problems that arise around this time.
"Students were asked to challenge the status quo; to ask 'why should we do things just because we have always done them?' and... to question whether nonreligious people should celebrate a religious festival?"
Previously, Paul told pupils there would be "no cards, no parties, no gifts and no Christmas tree."
"Christmas is a day celebrating the birth of Jesus and should be a time of good will to all, yet it can be a very stressful, expensive, argumentative and lonely time," she said.
However, she added, "If the arguments are good enough, we might see fairy lights in Lady Lumley's once more."