Florian Reiss (フロリアン・レイス Furorian Reisu?) was the youngest daughter of Rod and his wife, the younger sister of Frieda, Dirk, Urklyn, and Abel Reiss, and the youngest half-sister of Historia Reiss, who was born the day after her.
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 waistband with white sandals.
In the year 845, when Wall Maria was breached, Grisha Yeager invaded the Reiss Chapel, 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.
- If Florian was still alive, she would have been about the same age as Historia.