| The subject of this article has no official name.|
It is a fan-given name as substitute for lack thereof, and should not be considered as part of the Attack on Titan universe.
|Even if the whole world hates you, your dad is the one person who is on your side. So promise me.. that you will return.|
|— Mr. Leonhart to Annie|
Mr. Leonhart is the father and trainer of Annie Leonhart. He comes from the same hometown that she, Reiner Braun, and Bertolt Hoover are from, and is somehow associated with the Titan workings outside the Walls. He relentlessly trained Annie to fight, using mostly kicks and the attacker's weight against them. Memories of his pleas for forgiveness later create an opening for Annie to crystallize herself before Eren Yeager has the chance to capture her.
Mr. Leonhart has a receding hairline with his blond-gray hair combed back. He appears to be a relatively short man, as his daughter is also very short, and well built for fighting as he is a trainer. He has only been seen wearing a light jacket over a white shirt with dark pants and shoes.
He seems to be a relentlessly strict trainer, not allowing his daughter to take breaks and yelling at her during the trainings. However, sometime before Annie's departure, he has a change of heart and apologizes to her. Saying that she come back someday, assuring her that he would always be on her side.
At some point before the fall of Wall Maria, Mr. Leonhart taught Annie fighting techniques that involved kicks and the use of the opponent's weight against themselves.
While Annie is trying to escape from Stohess District transformed in her Titan form, she has memories about her father. They are in front of a cabin, surrounded by trees, and several punching bags can be seen. Her father apologizes to her, saying that it is too late to ask for forgiveness. However Mr. Leonhart tells her something: even if the whole world hates her and treats her like an enemy, he will always be by her side. He then tells her one last thing: to promise him that she will come back.
This memory triggers her hardening ability, encasing her into a crystal cocoon and allowing her to avoid interrogation, although she is captured and placed underground.
While waiting for the Survey Corps to arrive in Shiganshina District, Bertolt recalls the moment during the battle for Trost when Reiner Braun pressured Annie into taking Marco Bott's vertical equipment, claiming that it would prove that she, and the father awaiting for her return to the Hometown, are different than the "evil race" within the Walls.
- Annie Leonhart - At first he seemed to be a strict and not very approachable father for Annie, though for some reason he later changed his mind and demonstrated his love for his daughter by tearfully hugging her and assuring her that he would always be on her side. This reaction seemed to deeply surprise Annie, indicating that it was not common in him until then.