Donna Harrison, 36, told the YEP that her 16-year-old son Cameron Thompson was waiting for his train home from his college in Saltaire to Pudsey when he noticed his phone battery had run out - leaving him unable to access the ticket.
He had left his wallet at home in a rush and panicked as he got on the train.
Cameron explained to the train conductor that he had no money or way of getting on his phone.
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To his credit, the train conductor was "fine" with his explanation, Donna told the YEP.
However, the conductor couldn't guarantee his colleagues would be the same when Cameron was due to change trains at Leeds Station.
While the conversation was taking place, a generous woman overheard Cameron speaking.
She offered to give Cameron enough money to buy a train ticket and said she hoped "someone would do the same for her son".
Cameron's mum Donna was astounded by the act of kindness.
She is now desperate to find the caring stranger as Cameron would "love to pay her back".
A post from Donna explaining what happened has gone viral on forum Leedsplace.
The post read: "To the lady that paid for my son Cameron a train home from Saltaire to Pudsey thank you so much, He had his ticket on his phone and his battery had died and he did not bring any money with him. Thought you might be on here."
Many readers praised the stranger's actions.
One said: "Good to know we still have some nice people out there."
Another added: "Some people are just fabulous.
Do you know who the stranger is?
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