This is a list of all the minor characters in the Haikyū!! universe who don't have pages on the wiki because there isn't enough information for them. The characters are mostly listed under the schools or organizations they're affiliated with.
- Karasuno High's Vice Principal: He first appears in Chapter 2 and Season 1, Episode 2. He's the vice principal of Karasuno High, who's known for his wig to cover up a balding head. He causes a lot of trouble for the Boys' Volleyball Team and it has gotten worse since Hinata and Kageyama's fight. In the beginning of the series, Hinata and Kageyama nearly got the club in trouble when they played a mini match against each other and knocked the vice principal's wig off his head; it ultimately landed on Daichi's head, traumatizing the captain for a while.
- Yū Ogasawara: He first appears in Chapter ___ and Season 2, Episode 6. He is one of Ikkei Ukai's students at his volleyball school. He quickly becomes friends with Hinata when the teenager joins the school. After the Spring High begins, Yū often accompanies his teacher and several other students to Karasuno's games and cheers on Hinata while chatting with Yachi.
- Mao Aihara: She first appears in Season 1, Episode 14. She is a member of the Karasuno Girls' Volleyball Club and wears the number two jersey in the Interhigh Preliminary match. After the match and hearing her teammate's comment about Michimiya, she reveals that she (Michimiya) is trying to stay composed because of the fact that she is their captain and that she is waiting for the chance to be out of sight to let her emotions overcome her. She was also with Michimiya and Sasaki when they greet the boys back after their victory against Seijō in the Spring High Preliminary.
- Chizuru Sasaki (Japanese: 佐々木千鶴 Sasaki Chizuru): She first appears in Season 1, Episode 16. She is a member of the Karasuno Girls' Volleyball Club and wears the number eleven jersey in the Interhigh Preliminary match. She is a second year. During the match, due to her poor receiving skills, the opponents often aimed their serves at her and stole a lot of points from her team. As a result, she blamed herself for their loss, but was comforted by Michimiya.
- Asuka Hirama: She first appears in Season 1, Episode 20. She is one of the girls who had come to cheer Aobajōsai, especially Oikawa, during the Interhigh Preliminary. She wonders why Karasuno couldn't get the serve even though it wasn't Oikawa's, and Takinoue explains to her the reason. She thanks him later after adding that the players are thinking about a lot of things whilst they are on the court. Although attending the volleyball match initially to support Seijō, at the end of the match they are seen clapping for Karasuno when they bow to their supporters.
- Manaka Ujiie: She first appears in Season 1, Episode 20. She is one of the girls who had come to cheer Aobajōsai, especially Oikawa, during the InterHigh Preliminary. Just like Hirama, she attended the volleyball match to cheer Aobajōsai on but can be seen at the end of the match clapping alongside her friends when Karasuno bows to their spectators.
- Kiyoshi-san: He first appears in Season 2, Episode 23. Not much is known about this man, other than that he attended the Aobajōsai vs. Karasuno match at the Spring High Preliminary to support Kyōtani. He was fundamental to the development of Kyōtani's character, as he was the one who had influenced the boy to cooperate with his teammates and face each other head-on if he wanted to perform at his best. Kiyoshi's words prove to be useful as when Kyōtani placed his trust on his team, they were able to spike successfully past their opponents.
- Yunohama: He is one of Shiratorizawa's pinch servers and holds the number 7. He is a second year and played in the match against Karasuno during the Spring High. He was later present during Ushijima's speech to his underclassmen before retiring. His main weapon is the jump float serve,
- Anabara: He is the coach for Johzenji High. It's been shown that he's only recently started coaching, most likely this year or the previous year. Because of him, Johzenji was able to get into semifinals. Anabara later organizes the First Year Training Camp with Coach Washijō.
- Seiji Okudake: He is the former captain of Johzenji who retired after Interhigh. He is a third year.
- Mika (Japanese: 美華 Mika): She first appears in Chapter 206. Mika is Daishō's ex-girlfriend who broke up with him sometime before the Tokyo Spring High Representative Playoffs, most likely because of his sole focus on volleyball. Unbeknownst to him, she'd attended his match against Nekoma and after seeing his determination, began to understand his interests better. She later approached him after his loss and comforted him, asking him to teach her volleyball sometime; they most likely have reconciled after this.