Captain Hannah Graf MBE (née Winterbourne) is a former officer of the British Army and a transgender rights activist.

Graf was a captain in the Royal Electrical and Mechanical Engineers and the highest-ranking transgender officer in the British Army, overseeing a company of a hundred soldiers.

After returning from a tour of duty in Afghanistan, in 2013, she began living openly as a trans woman and became the highest ranking transgender person in the British Army.

[6] In 2018, she was appointed a Member of the Order of the British Empire by Prince William, Duke of Cambridge for "services to the LGBTQ community in the military".

[9] In 2020, the couple had their first child;[10] their experience as transgender parents was broadcast later that year in the Channel 4 documentary Our Baby: A Modern Miracle.