In an interview published by Die Zeit newspaper on Wednesday, Hitzlsperger says "I am expressing my sexuality because I want to promote the discussion of homosexuality among professional athletes."
The 31-year-old Hitzlsperger says he felt now was the right time, four months after retirement following a career in England, Italy and Germany, to approach a subject he feels is "simply ignored."
Hitzlsperger played 52 games for Germany from 2004-11. He also played for Aston Villa, Stuttgart, Lazio and Wolfsburg.
He says "only in the last few years did it dawn on me that I would rather live with a man."