The Young and the Restless is an American CBS soap opera which debuted on March 26, 1973. This is a list of its characters that debuted in 2021, in order of first appearance. Meredith (Evelina Martinez), the caregiver of Chelsea Lawson (Melissa Claire Egan), debuted in January, as did specialist Lena Cavett (Dana Sparks). Tara Locke, a woman that Kyle Abbott (Michael Mealor) had had an affair with, was introduced in March, with her husband, Ashland (Richard Burgi/Robert Newman) debuting later that month. Sutton Ames, played by Jack Landrón, debuted in April, followed by Harrison (Kellen Enriquez/Redding Munsell), the son of Tara and Kyle, in May. Detective Denise Tolliver (Telma Hopkins) made her first appearance in June, with Danny and KJ, played by father and son Keith Carlos and Keith Carlos, Jr, respectively, also making their appearance that month. Jesse Gaines (Jamison Jones) made his first appearance in September, whilst Kim Dunaway, played by Roxanne Hart, debuted in November. Additionally, several other characters appeared throughout the year.

Meredith Meredith, played by Evelina Martinez, made her first appearance on January 6, 2021, remaining until April 2021. Meredith was introduced as the caregiver of Chelsea Lawson (Melissa Claire Egan). In real life, Martinez is a close friend of Egan. The two enjoyed working together and found it fun, with Martinez writing on Instagram, "Chelsea is well taken care of!!! Nurse Meredith is on her side", whilst Egan wrote "How lucky am I that my dear friend Evelina Martinez was cast as my nurse! She's fantastic!" Candace Young from Soaps She Knows found the casting to be "something of a trend" due to Egan's husband, Matt Katrosar, having played two roles in 2020 on the soap, which was due to COVID-19 social distancing guidelines.

Meredith is the personal nurse of Chelsea, who takes care of her when she is immobilized from a stroke. She later becomes Chelsea's sole caregiver but moves out when she quits, with Chelsea's best friend, Chloe Mitchell (Elizabeth Hendrickson), taking over.

Lena Cavett Lena Cavett, played by Dana Sparks, made her first appearance on January 7, 2021, and made multiple appearance throughout the year in a recurring role. She is introduced as a specialist who works with stroke patients. Sparks wrote on Instagram that she was happy to be cast on the soap. Sparks has described the character as "kind" but "direct", as well as very grounded and in a very understanding, compassionate way". Sparks added "I play her as doing the best she can to help the situation, whether it's being honest or encouraging". Sparks had previously appeared on another soap opera, Passions, from 1999 to 2007.

Adam Newman (Mark Grossman) hires Lena, a specialist doctor, to help with the recovery Chelsea Lawson (Melissa Claire Egan), who has suffered a stroke and cannot move or speak. Lena promises to be straightforward about Chelsea's prognosis and later tells Chelsea to not get discouraged, though she avoids answering Adam's question about the likelihood of Chelsea recovering. When Chelsea does not show improvement, Lena suggests to Adam that depression might be hindering Chelsea's process, and recommends a psychiatrist. It is later revealed that Chelsea is making progress on her own but is tricking Lena into thinking she is still immobile.

Tara Locke

Tara Locke, portrayed by Elizabeth Leiner, made her first appearance on March 1, 2021. Rebekah Graf was initially hired to portray the role, but the role was recast with Leiner due to scheduling conflicts. She was introduced as the married woman that Kyle Abbott (Michael Mealor) had had an affair with, which produced a son, Harrison (Kellen Enriquez). Amy Mistretta from Soaps She Knows speculated that Tara's arrival could "Blow Kyle's World Apart" and "put a damper" on Kyle and his girlfriend Summer Newman (Hunter King)'s "ongoing quest for a bright future". Harrison and Tara's and husband Ashland (Richard Burgi/Robert Newman) were later introduced. Tara left the show when the character was arrested for stealing, with Leiner making her last appearance on August 6, 2021.

Richard Simms from Soaps She Knows put Tara on his list of the most hated soap opera characters, commenting that "Although she hit Genoa City with a legendarily malevolent husband, adorable moppet and lust-filled backstory, Elizabeth Leiner's Young & Restless alter ego was soon reduced to a Kyle-obsessed vixen who wasn't really all that vixenish." Charlie Mason from the same website criticised Tara's writing and characterisation, saying that the character was given "no edge" and that the show transformed her from "hot new love-to-hate character" to a character he could not "be bothered to care" about. Mason noted that the character was supposed to be "seductive", "intriguing" and "vixen" and that it was not Lanier's fault. Mason also criticised the revelation that Tara was embezzling from her own company. Mason and Simms named Tara as the "Biggest Waste of a Character" of 2021 in American soap operas, writing that the character had "potential to be a supervixen on par with old-school Jill or Lauren", but instead was written "with all the flair of a limp dishrag, rendering her about as interesting as a paperweight (and as likely to scheme her way out of a tight spot)" to the point that "no one even cared enough to cheer" when she was written out.

Ashland Locke

Ashland Locke made his first appearance on March 11, 2021, played by Richard Burgi in a recurring role. The character was referred to as an "uber successful tycoon with a reputation for being a shrewd businessman", who comes to town to oversee a bidding war between the Abbotts and the Newmans. The character was recast with Robert Newman in 2022. It was later reported that Burgi had been let go for violating the soap opera's COVID-19 policy, which he said was inadvertent. In July 2022, Newman exited the role, with the actor confirming the news on social media and thanking his fans. Of his exit, Newman told fans, "I very much enjoyed playing the character, and I hope you enjoyed seeing me in the role. I know for some of you, it was a tough transition from Richard's [Burgi] work, but I really, really enjoyed playing the character and working with these fantastic people". Ashland departed after being killed off in a fight with Nicholas Newman (Joshua Morrow).

Prior to his introduction, Amy Mistretta from Soaps She Knows referred to the character as a "ruthless business mogul". Richard Simms from the same website referred to Ashland as a "legendarily malevolent husband". Simms, alongside Charlie Mason, later wrote that Ashland was the "Second-Best New Character" of 2021 in American soap operas, calling him the "Locke Ness Monster", but wanted the soap to show "just how bad Richard Burgi's Big Bad is instead of merely telling us over and over again that he's powerful and scary". The following year, they called Burgi's firing from the soap as the "Biggest Shock, On Screen" of 2022 in American soap operas. Following the news of the recast, Mason noted that whilst it was a "bummer" that Burgi had departed, the soap "couldn't have picked a finer successor for him than Newman". Mason also noted that Ashland and Victoria's pairing was one of The Young and the Restless "biggest successes of 2021". Simms referred to Burgi's departure as a "twist nobody saw coming" and noted that Burgi had joined the soap to "great fanfare", as well as noting that the "unexpected pairing" of Ashland and Victoria "almost immediately caught fire" rather than a love triangle between Tara, Kyle and Summer. However, Mason and Simms later placed Ashland as the "Least-Missed Character" of 2022, writing:

Maybe it was the fact that Young & Restless Ashland didn't live up to his pre-introduction hype. Maybe it was that the part had to be recast mid-story. Or maybe it was that even in death, he remained the most talked about person in town. As the saying goes, "How can I miss you if you won't actually leave?"

Sutton Ames

Sutton Ames, played by Jack Landrón, made his first appearance on April 5. His casting was announced the previous month. Sutton was introduced as the father of established character Naya Benedict (Ptosha Storey) and the grandfather of Hilary Curtis (Mishael Morgan), Amanda Sinclair (Morgan) and Imani Benedict (Leigh-Ann Rose).

Sutton is part of a powerful politician family and he forced Naya to give away her twins Hilary and Amanda. Years later, he is accused of causing the death of the twins' father, Richard Nealon, who died in a car crash. Naya asks Amanda, a lawyer, to represent Sutton, which she agrees to. Amanda later meets Sutton and is angry at him for making Naya give her and Hilary up. Sutton understands her anger but says he does not regret his decision. Amanda warns him that she can lose the case as she has not worked in criminal law before. Sutton reveals that he followed Amanda and Hilary's lives and careers and is impressed with what they accomplished, and suggests that taking on his case will help her career and give her a chance to get to know her family. Amanda and Sutton agree the keep the relation private. A few weeks later, Sutton is impressed with Amanda's work and invites her to his house to meet the rest of the family, with Amanda emotionally accepts. She has a lovely time and Sutton gifts her some photos, and tells off Naya for not spending time with Amanda.

Sutton gets frustrated at Amanda for not following the defence strategy that he wants. When Amanda learns that Richard knew she existed and went looking for, Amanda starts to suspect that Sutton is hiding something and ends up dropping the case when she realises that Sutton really was behind Richard's death. Naya turns herself in and Amanda becomes determined to make Sutton face justice. With the help of Victor Newman (Eric Braeden), Amanda is able to get a confession from Sutton, who is arrested for his crimes. Sutton later visits Amanda at her home and asks for leniency, which she refuses. Sutton tries to record Amanda saying that she got him arrested as a grudge against him in order to discredit her in court, but Amanda gets the recording and gives it to the DA. Sutton is later found guilty of his crimes and sent to prison.

Chris Eades from Soaps In Depth noted that the character has a "whole lot of complicated backstory".

Harrison Locke

Harrison Abbott (also Locke) made his first appearance on May 14, 2021, played by Kellen Enriquez. The character has been referenced earlier that year when it was revealed that he is the biological son of Kyle Abbott (Michael Mealor) and Tara Locke (Elizabeth Leiner), though Harrison had grown up believing Tara's husband, Ashland (Richard Burgi/Robert Newman), was his father. It was reported that Harrison's debut could force Kyle to publicly announce that he is Harrison's biological father. The character departed later that year but returned in 2022, following the departure of Mealor. In 2024, the role was recast with Redding Munsell, who made his first appearance on April 12 of that year.

Years after Harrison is conceived, Kyle confronts Tara, knowing that Harrison looks like him and that Tara was not having sex with her husband, Ashland, when they had the affair. Tara admits that she had a DNA test done which confirmed that Kyle is the father. Tara tells Kyle to not tell Ashland about Harrison. Over the months, Tara tells Kyle things about Harrison and shows him pictures before eventually introducing him to Kyle and his fiancée, Summer Newman (Hunter King/Allison Lanier).

In 2021, Candace Young from Soaps She Knows called Harrison a "Cutie Patootie" and believed it was "safe to assume" that Harrison's debut would cause "some amount of upheaval". Michelle Moro Parkerton from Soaps In Depth called Harrison a "sweet little boy" with "adorable curls" and noted that he had "certainly been a hot topic of conversation" even prior to his first appearance.