Ni Hao, Kai-Lan

Kai-Lan (voiced by Jade Lianna Peters) is a playful, adventurous young girl with a big heart. She has black hair that she wears in two space buns with red flowers. The character is often shown wearing a blue t-shirt, orange shorts, and red sneakers. She wears a necklace with a green jade pendant around her neck in every episode. Kai-Lan tries to help all of the characters she meets. She wants to help her friends when she sees that they are not happy or acting out in temper tantrums, even when her friends refuse to compromise, she fails to display actual anger. She gives others a chance to change their minds and do the right thing. Kai-Lan values her family (throughout the show only her grandpa, Ye-Ye, is seen) and she is very fond of her friends: Rintoo, Tolee, Lulu, and Hoho. Kai-Lan speaks both English and Mandarin Chinese. She loves to share her language, her culture, and her playtime with her animal friends and the viewers at home. Kai-Lan is a natural leader, but she is also thoughtful and always ready to help someone in need. Her favorite animal is a dinosaur. In her music group, she plays the tambourine.

Rintoo (voiced by Jack Samson) is a rambunctious and energetic 5-year-old young tiger with a frontal lisp who often acts before he thinks. He often fails to see when he is having a temper tantrum and needs his friends to subtly guide him towards learning to act with more manners. Rintoo enjoys playing sports and he is an avid fan of dragons and racecars. Rintoo hates losing at anything and will often do a tiger roar when he feels angry that he lost. However, he is always willing to correct his behavior and work better with his friends. Rintoo, along with Hoho, is often seen as the character who get into trouble. He plays the xylophone in Kai-Lan's music group.

Tolee (voiced by Khamani Griffin) is a gray 5-year-old koala who loves pandas and eating fruit, especially apples, bananas, and pineapples. He is intelligent, sensitive, and always thinks before he acts; however, Tolee often overthinks and worries too much. He dislikes feeling left out of the group, such as when his friends are playing a game where they need to pair up and everyone is paired up before he is. Tolee is Rintoo's foil. Whereas Rintoo is talkative and acts before he thinks, Tolee is thoughtful and will deeply consider his actions before making a decision. When Tolee feels sad or has his feelings hurt, he starts to cry, but his friends can always cheer him up. Tolee loves playing with his friends. Kai-Lan and her friends can always rely on him for good ideas. Tolee also has a stuffed panda that he affectionately named Pandy. Tolee is the vocalist in Kai-Lan's music group.

Lulu (voiced by Beverly Duan) is a sweet and intelligent 6-year-old pink rhinoceros. Lulu has a red balloon tied around her horn that helps her fly in the sky. She likes to help her friends, using her red balloon to fly to their aid when they call her name. Lulu gives others a chance to try their hands at tasks even when she herself might have an easier time with them. Lulu values all of the characters she meets and is always friendly and willing to help. She demonstrates compassion and diplomacy, and will often be the first (besides Kai-Lan) to compromise and work out a resolution among her friends. Lulu enjoys dressing up like a princess, having tea parties, and dancing to disco music. She tries to introduce her traditions and customs subtly and without compulsion to those who are not familiar with them. Lulu lives in a floating castle in the sky. Lulu is also a musician, skilled at playing the piano and singing. She's indicated to be best friends with Kai-Lan. Her instrument in Kai-Lan's music group is the keyboard, and her favorite fruit is the lychee.

Hoho (voiced by Angie Wu) is an energetic white 3-year-old monkey and is the youngest of Kai-Lan's friends. When he participates in activities, he often goes first. He is full of energy and enjoys being the center of attention. He is a picky eater and can be stubborn towards change such as when his friends want to play a different game. Despite his initial difficulties towards accepting new foods and games, Hoho often to his surprise finds that he loves the thing that he was reluctant to try. Whenever he jumps a springing sound can be heard. He can often be found jumping on his friends' heads or playing his turntables as the DJ in Kai-Lan's music group. Aside from his turntables and his friends, Hoho loves bananas.

Ye-Ye (voiced by Clem Cheung and Ben Wang) is Kai-lan's playful, thoughtful, and caring grandfather. He was born in Hong Kong and lovingly passes on his exciting traditions to his granddaughter. He provides Kai-lan with gentle guidance, leading her to find her own answers, at her own pace. (Kai-lan's parents and other grandparents are not known.) He can play the tuba, and enjoys picking apples and making dumplings for Kai-lan and all her animal friends.

At the start of almost every episode, Kai-Lan wakes up Mr. Sun so she can start her day. With the help of the viewer, Mr. Sun rises and showers down smiling sun fuzzies to Kai-Lan and she gets tickled by them. He also knows how to play the trumpet, so Kai-Lan and the ladybugs (playing the pipa) join him as a little music group at the beginning of Tolee's Rhyme Time and later joins Kai-Lan and her friends in the music show.

In one corner of Kai-Lan's backyard is a teeming mini-metropolis of ants called Ant City. The ants serve very important roles in the community: they deliver mail, they build things, and they love to play with Kai-Lan and her friends. San San is their leader along with his two right-hand ants, Bubu and Fufu.

San San is voiced by Zachary Gordon, Bubu is voiced by Luke Manriquez, and Fufu is voiced by Kyla Rae Kowalewski.

• Howard (voiced by Khamani Griffin) is an owl who first appears in "The Dragonboat Festival." He delivers letters and only speaks in hoots.
• Mr. Fluffy (voiced by Elan Garfias) is a hamster and baker who first appears in "Everybody's Hat Parade."
• Mei Mei (voiced by Laura Marano) is a shy blue polar bear.
• Stompy the Elephant (voiced by Hsiang Lo) is a big, playful blue elephant who made his first appearance in "Safari Pals." Nothing makes Stompy happier than being able to play with his friends.
• GuNaiNai (voiced by Ming-Na Wen) is Kai-Lan's great-aunt and YeYe's sister. She appears in "Kai-Lan's Trip to China."
• Xiao Xi Gua (meaning "little watermelon") is a baby panda. He appears in "Kai-Lan's Trip to China."
• The Peeking Mice are little, black mice who are often seen playing music. They are voiced by assorted members of the cast.
• The Scotland Rabbits playing tunes on their bagpipes.
• Mr. Hoppy (voiced by E.G. Daily)is a green frog who speaks in ribbits. In the episode "Kai-Lan's Carnival", he is shown to own a game booth called "Mister Hoppy's Hop-and-Splash" where the player has to throw a ball to sink a lilypad.
• The Monkey King (voiced by Jack Cygan) is a monkey superhero who asked Kai-Lan and her friends for help in a magical kingdom where the foxes and the bears never talk to each other. He appears in "Princess Kai-Lan."
• The Fox King is a fox in The Fox Kingdom. He creates magic bamboo forests to keep the bears away. He usually gets mad, and he could not get his sleep and talk to his friends, because of the dancing bears.
• The Foxes are red foxes that live in The Fox Kingdom. They sing loudly to annoy the Bear Queen. The Fox King's Guards wear Chinese Men's Hats and wear green.
• The Bear Queen (voiced by Lucy Liu) is a bear in The Bear Kingdom. She creates a moat to keep the foxes away. She is usually mad, and she could not get her sleep and talk to her friends, because of the singing foxes.
• The Bears are brown bears that live in The Bear Kingdom. They dance to make the ground shake, thus angering the Fox King. The Bear Queen's guards wear knights' helmets and purple armor.

The success of Ni Hao, Kai-Lan spawned its own video game series, supported by various gaming consoles and platforms:

• Nickelodeon's Ni Hao, Kai-Lan: Super Game Day (Nintendo DS, PS2) – released, October 26, 2009[9]
• Nickelodeon's Ni Hao, Kai-Lan: New Year's Celebration (Wii) – released, November 5, 2009[10]