Maisie Elwin from Harpley had her locks trimmed on the last day of term at the village primary school.
She has so far raised more than £750 from sponsorship and donations.
Both the hair and the money will be going to the Little Princess Trust - a charity which provides real hair wigs to girls and boys who are undergoing cancer treatment.
Mum Sarah Elwin said Maisie grew her hair specially before having 10ins cut off.
'She wouldn't let me touch it for two years,' she said. 'She's very strong-willed.'
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