Shiyi Ying, 25, was given permission to take to the stage towards the end of the ceremony at Southampton University to pop the question to Yu-Yen Ou, 24.
He said: "Deep inside I know you are the only one I can share the rest of my life with," before she accepted.
Vice-Chancellor Professor Don Nutbeam said it was "certainly a first" in his 25 years attending graduations.
Both students were receiving their masters degrees. Mr Ying, from Beijing, had studied for an MSc International Management and Ms Ou, from Taipei, had studied MSc International Financial Markets.
After Ms Ou said yes the couple hugged - prompting applause from fellow graduands, guests and staff gathered inside the theatre.
Prof Nutbeam said: "I'd like to offer the couple huge congratulations and every best wish for the future."
A university student has proposed to his girlfriend during a graduation ceremony.