| The subject of this article is anonymous.|
The name used is an alias, nickname or surname found in an official source, but the actual in-universe name of this person is unknown in this continuity.
|Even if every other creature alive comes to hate you, your father will always be on your side... So please. Promise me...that you'll come back!|
|— Mr. Leonhart to Annie|
Mr. Leonhart (レオンハートさん Reonhāto-san?) is an Eldian living in the Liberio Internment Zone and is the adoptive father of Annie Leonhart. He had trained his daughter to be a Warrior candidate which later led to her selection as inheritor of the Female Titan's power.
Mr. Leonhart has a receding hairline with his dark hair combed back. He appears to be a relatively short man, 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. During the Liberio festival, he is seen wearing a beret and using a cane. He is disabled and unable to walk straight.
He was selfish at first with Annie and his goal was to solely train her into becoming a Warrior of Marley so that he could have a wealthy life. He seemed to be a relentlessly strict trainer, not allowing his daughter to take breaks and yelling at her during the training sessions. However, sometime before Annie's departure, he had a change of heart and apologized to her, he finally saw her as his true daughter saying that she come back someday, and assuring her that he would always be on her side. He seems to be very motivated to see Annie again.
Years ago, Mr. Leonhart was relocated to an internment zone from another country after it was discovered he has Eldian blood. He later adopted a baby girl who was abandoned for similar reasons. He raised her with the intention of having her become a Warrior so that he could improve his own life. Mr. Leonhart taught Annie fighting techniques that involved kicks and the use of the opponent's weight against themselves. Because of his harsh treatment, Annie eventually lashed out at him during training, crippling him for the rest of his life.
Before Annie left Liberio to partake in the Paradis Island Operation, Mr. Leonhart apparently had a change of heart, apologizing to her for everything he had done and claiming that becoming an honorary Marleyan no longer meant anything to him. Mr. Leonhart assured her that even if the whole world hated her and treated her like an enemy, he would always be by her side. He asked her only to promise him that she will return home.
After impressing Eren Yeager with her fighting technique during training, Annie mentions that her father was the one who taught it to her. She goes on to deride the ideals he held, comparing them to Eren's, and claiming that they have nothing to do with reality.
While Annie is trying to escape from Stohess District transformed in her Titan form, she remembers the last words her father said to her before she left Liberio. 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 her father who is waiting for her return to her hometown, are different than the "evil race" within the Walls.
Mr. Leonhart attends Willy Tybur's production at the Liberio festival, being seated in reserved seats meant for honorary Marleyans. He speaks with Karina Braun about Bertolt Hoover's father having passed away, and Mrs. Braun discusses the pride of both Annie and Bertolt having devoted their lives for Marley. Mr. Leonhart denies this, adamantly stating that Annie is not dead, as she promised to come home.
Mr. Leonhart listens apathetically whilst Willy delivers his speech, seemingly caring little for his revelations on the true history of the Great Titan War, or his reasons to wage war on Paradis Island. After Willy officially declares war, the Attack Titan comes forth, killing Willy and sending building wreckage into the crowd. Mr. Leonhart avoids the carnage and tries to assist Mrs. Braun in escaping.
Along with all other Subjects of Ymir, Mr. Leonhart is spoken to by Eren Yeager through the Founding Titan. Mr. Leonhart drops his shopping and falls to his knees, panicking about the declaration that the lives beyond Paradis Island will be exterminated.
Mr. Leonhart is among a group of Eldians who desperately try to convince Liberio's guards to allow them to leave before Eren arrives with the Wall Titans. Unfortunately, the guards do not believe the crowd, as only Eldians were able to see Eren's broadcast, and accuse the Eldians of plotting to escape their internment camps. The guards begin to detain the group and Mr. Leonhart, recalling Annie's promise to return to him, begins lashing out at them.
- Annie Leonhart - Annie was an Eldian baby abandoned at birth and Mr. Leonhart adopted her. His goal was to solely train her into becoming a Warrior of Marley so that he could have a wealthy life while Annie looked to her adoptive father as a source of strength. Annie would hold him in contempt for his selfish desires. After time passed, Annie lashed out at her father for all she had endured up to that point. She left him crippled and unable to walk straight again. Yet, Mr. Leonhart rejoiced because she had become as strong as he wanted. However the day Annie was sent to Paradis; he changed his mind and finally saw her as his true daughter, he regretted his actions in making her become a Warrior and begged her to promise him to come home. Thus, Annie's views on her adoptive father changed and she has since vowed to fulfill that promise.
- Karina Braun - While they knew each other, they did not seem to be close. During the Liberio festival, Mr. Leonhart said they had not met since Karina's son, Reiner Braun, returned to Marley four years earlier.