The 19-year-old singer dressed up for the occasion by wearing a smart black blazer and a striped T-shirt, as he posed for photographs alongside his 22-year-old sibling, who smiled proudly in her cap and gown, reported Daily Mirror.
He uploaded pictures to his Instagram with the caption, "My sister graduated today. She's all clever and that."
Harry, 19, often visited Gemma during her time studying in Sheffield as he was spotted partying at her halls of residence and in the student union when he had time off from his busy schedule with One Direction.