Yū Nishinoya (Japanese:
Nishinoya is the shortest member in the team, standing at 159.3 cm (now at 160.5 cm as of chapter 207). Despite his shorter stature, he has a fairly muscular build. He regularly styles his wild dark brown hair by ruffling most of it upwards, adding 10 cm to his height; the tiny tuft of hair that falls over his forehead appears to be bleached a dirty blond. His eyes are brown and slanted.
He tends to wear brightly colored shirts that typically have a random four-character idiom printed on either its front or back, such as "One-Man Army" or "Three-Point Headstand". In games, he wears an elbow pad on his right arm in addition to his uniform, unlike the rest of the team.
Nishinoya is a very energetic and temperamental person. His boisterous nature and crazy shenanigans can attract unwanted attention quite easily, which often goes badly for him. Although he hardly ever worries about the consequences of his actions (and may even revert to violence in order to vent out his anger on certain occasions), he is surprisingly considerate of his friends' feelings and insecurities.
He has a quirky habit of spontaneously coming up with ridiculous names for the moves he executes while practicing receives. He is also unexpectedly shy when it comes to talking to girls he hasn't met before.
Like Tanaka, Noya has a large interest in Kiyoko Shimizu. Together, they try to approach her but are ultimately ignored. They cause a bit of a ruckus when this happens and are usually scolded by somebody, usually Daichi. When the series officially introduces Noya, he energetically approaches Kiyoko, which results in an off-screen slap. Noya returns with a red cheek and a smile.
Noya can be extremely impatient, excitable and impulsive. As Tanaka puts it, "he simply gets too fired up for his own good." He doesn't bother to filter his words and is therefore prone to blurting out whatever he's thinking in a loud and tactless manner. In-game, however, his attitude changes drastically: he becomes incredibly focused and serious, remaining calm and doing everything in his power to provide the support his team needs until the very end. For this reason, everyone in the volleyball club respects him greatly. He is shown to be incredibly hard-working, once even continuously practicing more than 200 spike-block receives to the point that his legs stopped moving.
Although he displays an incredible feat of confidence and fearlessness countless times, Nishinoya admits to himself that he was a "huge scaredy-cat" when he was a kid. He had many fears, which resulted into his grandfather training him so he could overcome those fears, teaching him that behind every fear is a wasted experience, and telling him to never be afraid to ask for help whenever the fear doesn't fade. This reflected Nishinoya's tenacity and courageous facade during matches, and served as an important matter in his character development sometime in the Nationals, due to the fact that he straight-forwardly tells the team about his childhood without a doubt even though he is being pushed into a corner.
Nishinoya is good at acting on the spur of the moment, adapting to the flow of the game as it is required. This turned out to be a vital asset to Karasuno in their revenge game against the famed "Iron Wall", wherein Noya made the split-second decision of using his foot in order to prevent the ball from hitting the ground since he knew he could not reach it with his hands in time. That move alone earned him the immediate astonishment and heartfelt praise of the entire stadium, including several volleyball veterans, a number of players from rival teams, and even his normally critical coach.
Height and reach, as of mid-November:
- Fingertip Height: 208 cm
- Jumping Reach: 302 cm (spike) / 290 cm (block)
- Libero Toss: Nishinoya distinguishes himself from other liberos with his participation in offense. Despite struggling with it initially, he is now capable of jumping behind the attack line and performing a libero toss either to Asahi or his other teammates in a synchronized attack. This is especially helpful under the circumstances where Kageyama is forced to make the first touch. However, the move is not without drawbacks: Given that it is effectively an all-out synchronized attack, there won't be anyone to defend again if it was blocked.
- Overhand Receives: Nishinoya originally has an obvious weakness in overhand receives and is particularly weak at receiving jump floaters. Since then, he has made immense improvements practicing with teammate Kinoshita. He is now better equipped to deal with different types of serves and spikes.
- Spiking: While playing as a libero, it is against the rules for Nishinoya to spike. In the extra Nisekyū!!, Nishinoya enters as a spiker in a volleyball beach tournament, where he demonstrates his ability to spike in an attack he called "Small Big Thunder".
- Favorite Food: Gari-Gari Kun! (Soda flavor)
- Current Concern: None!
- Nishinoya wears white gym shoes with red accents.
- He has gotten suspended from school for a week and suspended from club activities for a month.
- He said that he came to Karasuno because of the uniforms (the girls' are cute and the boys' black uniforms look super cool) and the short distance between the school and his home.
- He is known, as the Guardian Deity of Karasuno High Volleyball Club.
- During the team's first training camp, Hinata didn't recognize Nishinoya due to the fact that after bathing, his normally swept-up hair was down instead, and thus decreased his height by 10 cm.
- If his listed height includes his hair when styled up, then Nishinoya is only 149.3 cm tall (or 150.5 cm after chapter 207).
- In the 35th Volume of the manga, Daichi says that he has never seen anyone who looks that good with a stick before.
- Nishinoya's hair when swept up is 10 cm (4 inches) tall.
- According to Tanaka, the only type of movie Nishinoya will watch is over-the-top action, where he usually yells in excitement in the middle of the film.
- His worst subject is contemporary literature.
- He attended Chidoriyama Junior High, a middle school in the Miyagi Prefecture.
- During Ennoshita's flashbacks of his first year, Nishinoya is seen with completely black hair; meaning he dyed his hair sometime after that year's summer vacation, but before the Newcomer's Match against Date Tech.  However, this clashes with Nishinoya's flashback to his childhood in the manga, where he is seen as a young child with his signature blonde streak. Whether his streak is natural or dyed is still to be confirmed.
- Asahi and Nishinoya are foils. Their birthdays are inverse (01/01 and 10/10), as are their heights and personalities (and even their name kanji contrast each other - respectively 'east' and 'west', 'peak' and 'valley', 'morning sun' and 'evening'). They are also the two best-known, talented, and accomplished members of the team other than Kageyama.
- His star sign is Libra.
- When asked about Nishinoya's name origin, Furudate said, "The evening sun that sets in the western valley! But I still think the name Yū doesn’t fit Nishinoya!"
- He is likely ambidextrous.
- He received the most votes for the libero position on the 'Dream Team' poll and was hence chosen as the libero on the Readers' Dream Team.
- In Haikyuu's first popularity poll, Nishinoya placed 3rd with 5,704 votes. In the second, he placed 6th with 6,852 votes.
- He is officially the series' third-biggest eater. 
- As a child, he 'was a huge scaredy-cat' who was 'scared of bugs, scared of dogs, scared of birds' and so on.
- He hates onions and moths.
- He fights with other players from other schools because he likes Kiyoko Shimizu and the players from other schools flirt with her.
- In the short chapter Nisekyū!!, Nishinoya is seen spiking.
- His favorite play is the Rolling Thunder.
- When Hinata was naming his back minus, Nishinoya advised Hinata to add Thunder to the name.
- Yū (夕) - Evening
- Nishinoya (西谷) - West Valley
- When he gets excited, Nishinoya has a habit of placing his hands on the shoulders of the nearest person and uses this to stabilize himself as he jumps up and down in the air, kicking his feet up so it almost looks as if he's attempting to do a handstand in mid-air.