Tom Hill, 19, is suing the Oxford, Cambridge and RSA Examinations board (OCR) for £100,000 damages.
Mr Hill, a former student at the independent Marlborough College in Wiltshire, believes the board failed to mark his English and history papers "honestly or competently".
The case for alleged breach of contract could prompt thousands of other students affected by the grading saga to take legal action.
On Friday it was revealed that 91,545 candidates will have their papers reviewed by OCR after an independent inquiry led by former Ofsted chief Mike Tomlinson found some students' results were downgraded at a late stage.
Many students have, in the meantime, taken up places at their second or third choice university, having failed to get the necessary grades for their first choice.
Oxford dream
Mr Hill from Buscot, Oxfordshire, needed three A grades to secure a place at Oxford University, but a U (unclassified) grade in a unit of his history A-level dragged his overall score down to a B and in English he was also awarded a B.
He claims that because OCR failed to grade exams fairly, his chances of becoming a lawyer have been damaged.
Mr Hill, who has not taken up a university place this year, told The Mail on Sunday newspaper: "I'm furious over what has happened.
"I wouldn't take legal action lightly but I think it is the only option I have."
His father, Graham Hill, said his son hoped to apply to read history next year.
"It is not just the grading we are unhappy about, it is the overall standard of the course," he said.