Sara Hegazy, 30, committed suicide on Sunday after leaving behind a note asking her family and friends to forgive her.
Hegazy rose to prominence after raising the LGBT rainbow flag at a concert in Egypt in October 2017.
Hegazy was among dozens arrested by Egyptian security forces following orders from the public prosecutor to investigate others who raised the rainbow flag at the same concert.
Activists paid tribute to Hegazy on social media, with some using the hashtag homosexuality is not specifically outlawed in Egypt, it is a conservative society and discrimination is rife.
Those arrested are subjected to anal examinations to determine whether they have had gay sex, which rights groups Amnesty International and Human Rights Watch say amount to torture.
