Florian Reiss (フロリアン・レイス Furorian Reisu?) was the youngest daughter of Rod and Lady Reiss, the younger sister of Frieda, Dirk, Urklyn, and Abel Reiss, and the youngest half-sister of Historia Reiss, who was born in the same year.
Florian was a small 10-year old girl with long black hair and light eyes. She was only ever seen wearing a plain white robe with a long white v-neck dress and a black waist band with white sandals.
In the year 842, Florian was not there to see the death of her uncle Uri Reiss, who inherited her ancestor or the First King's power to her older sister Frieda Reiss. This was perhaps due to her being 7 at the time.
In the year 845, when the Wall Maria crashed, Grisha Yeager invaded the Reiss home territory, turned into a Titan, and killed most of Reiss family members including Florian Reiss herself. According to Rod Reiss, she was "stomped" together with her mother in Grisha's feet. Before Grisha attacked, she fearfully clung to her mother.
- In the Kodansha English translation of chapter 63, Florian is mistakenly referred to as a male.