Ty Lee was a cheerful and energetic teenage girl hailing from the Fire Nation. The daughter of a nobleman, she attended the Royal Fire Academy for Girls with her longtime friends, Princess Azula and Mai. As a child, Ty Lee dealt with six sisters that shared identical appearances with her, which caused her to feel a loss of individuality, a longing to be a distinct, recognizable person, and a desire for attention from other people.
Ty Lee was bubbly and outgoing, yet slightly airheaded. She was a direct contrast to Azula's innate cruelty and Mai's constant torpor. She took delight in her acrobatic abilities, never missing an opportunity to show them off. Because of her upbringing as part of an identical set of seven sisters, Ty Lee craved attention and recognition. This is what may have led her to develop her acrobatics in the first place, as well as her running away to join the circus. These attention issues also caused her to be a bit of a flirt, which is also why, according to Mai, she needed the affection of ten boyfriends.
Ty Lee showed a strong sense of loyalty to her friends, Mai and Azula. Despite her obvious differences from Mai, she had a deep respect for her and they often made an effective fighting duo, teaming up numerous times in the series. Ever since childhood, Ty Lee also considered Azula as a friend but, as she got older, that loyalty seemed to have been out of fear of the princess. When she first refused Azula's request that she join her search for the traitorous Zuko, Azula persuaded Ty Lee by endangering her life during a circus performance. For some time, she never disobeyed Azula's orders. However, her breaking point came at last at the Boiling Rock, during Azula's attempted murder of her own brother and Ty Lee's childhood friend, Zuko. When the rope holding Zuko's gondola was about to be cut, potentially sending Zuko along with several prisoners and friends plummeting to their deaths, Ty Lee showed concern while Azula smirked next to her. After Mai helped Zuko and his friends escape the prison, Azula threatened her life. Seeing Mai in the face of Azula's terrible rage and fearing for Mai's safety, Ty Lee attacked Azula, ending up in jail but finally conquering her own fears and taking a stand against her "friend" after months of obedience.
Ty Lee was known not to hold grudges against her enemies despite their encounters on the battlefield. This was evidenced by her eventual bond with the Kyoshi Warriors, whose confinement she was partially responsible for. She was able to establish a fairly strong friendship with the group while they were imprisoned together. She also showed affection for Sokka, despite having fought him under the orders of Azula.
She was known to be close to animals. In Ba Sing Se, she was seen teaching Bosco acrobatic moves before Toph earthbent her to the ground.
Ty Lee often came off as superficial, which was demonstrated for the first time when she affirmed her beauty to a Kyoshi Warrior and a second time when she warned her friends about the negative energy of their serious conversation, which she said would give them acne. This attribute may have originated with her profession as a circus performer, her appearance perhaps making her a more popular attraction among the audience - especially since this experience followed an upbringing that had left her attention-starved.
Ty Lee was extraordinarily acrobatic. Even at a young age, she was able to execute cartwheels and somersaults in mid-air with a skill that surpassed even the agile Azula's. Her acrobatic abilities allowed her to join the Fire Nation circus, where she frequently performed high-wire acts with balance and grace. People traveled for miles to see her perform. Because of this, she was very fast and agile in battle, able to outmaneuver almost any opponent she came across and jump exceptionally high and far even from a stationary position. Her abilities allowed her to dodge dozens of powerful earthbenders, who were unable to land a hit on her. She was also very flexible, able to contort herself into positions nearly impossible for an ordinary person to achieve and walk on her hands without any difficulty. These abilities allowed her to scale almost any surface very quickly and squeeze through most barriers and small spaces.
Ty Lee's most defining ability was her mastery of pressure-point martial arts, or chi blocking. She could strike sequences of pressure points, immobilizing her enemies to various degrees. She had the ability to paralyze a single body part or an opponent's entire body. This technique allowed her to block certain chi paths in benders to compromise their abilities. This made her especially dangerous to warriors like Katara, who relied solely on their bending and possessed no secondary fighting skills. She was so powerful that outside the walls of Ba Sing Se, she was able to defeat dozens of powerful earthbenders within seconds. However, if her target had faced her before or was expecting her attacks, the effectiveness of her chi blocking decreased as her opponent took measures to prevent her from using the technique. After fighting her before, Suki was able to avoid her attacks at the Boiling Rock and Katara and Sokka were also able to effectively counter her when facing her again. She took Azula by surprise when she was about to strike Mai because, although the princess was familiar with Ty Lee's fighting style, she had never faced her as an opponent. While Ty Lee was imprisoned with the Kyoshi Warriors she had mentioned that she gave them "a few chi blocking lessons" and in return she was allowed to join the group.
- In the Taiwanese translation, Ty Lee's name is written as 泰麗 (tài lì), meaning "calm and beautiful".
- As shown in "The Chase" and stated by "Avatar Extras", when Ty Lee uses her chi blocking on a non-bender, it causes their body parts to go limp and makes them unable to move them.
- Ty Lee appeared to have a crush on Sokka, as she mentioned that Sokka was cute. When she, Mai and Azula found Aang, Sokka and Katara, she said, "Azula, you were right — it was the Avatar... and friends", directing the comment toward Sokka as her look grew more flirtatious. Later, when confronting Sokka in the Earth King's throne room, she cheerfully described their fight as dancing.
- Ty Lee may not have been imprisoned at the Boiling Rock since the Kyoshi Warriors, except for Suki, were held elsewhere, unless the other Kyoshi Warriors were transferred to the Boiling Rock after Suki escaped.
- Ty Lee was the second known outsider to join the Kyoshi Warriors, Sokka being the first. She was also the first known Fire Nation native to join them.
- Ty Lee was one of the few members of the Fire Nation that did not have black hair or golden eyes.
- According to "Avatar Extras", Ty Lee was described as the Avatar version of a Valley Girl.
- In the non-canonical "School Time Shipping" episode, Ty Lee was shown to have some attraction to Haru.
- Ty Lee went to the circus because she did not feel special among her six sisters. Ironically, by the end of the series she joined the Kyoshi Warriors, who all dressed and looked alike.
- Ty Lee's chi blocking fighting style was strikingly similar to Gentle Fist, the fighting style of the Hyūga clanfrom the popular manga/anime series Naruto and its sequel Naruto: Shippuden; both use martial arts to block a person's chi, although the Hyūga clan's style involves blocking the chakra flow in the person.
- Ty Lee claimed to be able to see people's auras. For example, she told Mai that she had an aura that was dingy, pasty, and gray.
- Ty Lee was the only person in the series that Azula ever apologized to.