Just like its sister series, The Big Bang Theory, Young Sheldon features a colorful cast full of funny oddballs trying to cope with the central figure, complicated genius Sheldon Cooper. Set in the fictional town of Medford, Texas, Young Sheldon explores Sheldon's relationships with his immediate family and allows the viewers to see them grow themselves.
Unlike the portrait that Sheldon used to paint during TBBT, the characters in Young Sheldon are not only likable but they are highly interesting and compelling, sometimes even more than the genius himself. A lot of the humor comes from their attempts to understand him, entertaining audiences along the way with a clever and effective mix of humor and heart.
Tam Nguyen
Sheldon's closest friend, Tam is the one responsible for introducing the boy prodigy to a lot of his life-long passions, like comic books and RPGs. Furthermore, Tam seems to be the only one, outside of Sheldon's immediate family, to put up with him. Equally, Sheldon seems to be the only one to be able to stand Tam's bad temper, implying they're together more out of circumstance than actual friendship.
Tam's appearances in the show become more sporadic as the show progresses. He has a very troubled home life, which explains his gloomy, pessimistic attitude.
Billy Sparks
Although Sheldon frequently exaggerates or literally lies about the events surrounding his childhood, calling Billy Sparks a bully is a stretch, even for him. Once, he even says Billy shoved a Mexican Peso up his nose.
Although Billy did show bully-like behavior at the beginning of Young Sheldon, he quickly becomes harmless and is often shown to almost enjoy Sheldon's company. Billy seems to harbor a still unrequited crush for Missy, although some fans think he will eventually become her future husband.
Pastor Jeff Hodgkins-Difford
Although Pastor Jeff is generally kind and far more logic than a lot of the members of his flock, he's still biased by his nearly blind faith. And while he often tries to find a common ground with Sheldon's highly logical point of view, to the best of his capacities, he's almost always defeated by the young boy and in one episode almost starts crying after one of their debates.
Pastor Jeff is a mostly likable figure that just begun to be more explored. Still, his cheery predisposition manages to overcome his willful ignorance, making him an entertaining character that's easy to root for.
Mary Cooper
Sheldon's deeply religious mother, Mary is a very close-minded and overprotective mother that doesn't always have her children's best interest at heart. A lot of her actions on the show can be seen as quite selfish, but she does them out of real concern for their well-being.
The Mary in Young Sheldon is less cynical than the one in The Big Bang Theory. She's not as overtly racist or demeaning, which makes her even more likeable. Her behavior can be quite annoying at times, especially with her stubbornness and extremely pious tendencies.
Sheldon Cooper
Being the protagonist of the show doesn't necessarily mean you have to be the most likeable character. Sheldon, true to his behavior in TBBT, is as idiosyncratic and compulsive in Young Sheldon. He shows dislike for the deeply religious community he lives in, and thinks less of his family because of their seemingly low intellects.
Sheldon also annoys his classmates and teachers at high school, has little interest in making friends (as he already has Tam), and enjoys being right, going to great lengths to do so. He does genuinely care for his family and has shown empathy for them on multiple occasions. However, and knowing the future that awaits the Coopers, it's easy to assume he'll become more inhuman, in line with the character Leonard first meets in 2003.
John Sturgis
Kind and extremely eccentric, Professor Sturgis is one of the first people with which Sheldon can relate to at an intellectual level. The professor not only bonds with Sheldon, but also with Connie, and their relationship is as charming as it is bonkers.
It is soon revealed that Professor Sturgis has severe mental health issues, which lead them to have a mental breakdown. Once he recovers, he ends his relationship with Connie, as he does not want her to go through the difficulties of dating him. A deeply sympathetic figure, played by beloved character actor Wallace Shawn, he quickly became a fan favorite.
Georgie Cooper
Sheldon's older brother, who enjoys torturing the boy genius, Georgie might seem like a prototypical bully at first glance. However, the more the series develops him, the more audiences understand his behavior. Georgie is deeply insecure about his own intellect and future, especially compared to Sheldon's. He has a natural talent for sales and business, which will eventually make him quite wealthy, but as of Young Sheldon, he doesn't have a way of knowing it.
A ladies man, his unrequited love for Veronica makes him mature, and by season 3, he's already showing signs on the put-together young man who will take care of the family once Sheldon leaves and George Sr. dies.
Connie "Meemaw" Tucker
Sheldon's loving grandmother, Meemaw is quite devoted to her extraordinary grandchild. She supports and encourages not only his intellect but also his more egotistical tendencies. She also cares for Missy and Georgie, and allies with them when their strict mother doesn't.
Meemaw is very practical and quite intelligent. She doesn't adhere to the strict Christian life that the rest of the town seems to adopt, and instead does her own thing. Relaxed, hilarious, and rather progressive, she's easily one of the best characters in the show who quickly steals the spotlight.
George Cooper Sr.
Perhaps because Sheldon talked about his father in such a negative light, audiences expected to really dislike the character in Young Sheldon. However, and to the surprise of everyone, George Sr. is shown to be not only deeply supportive of his family but also very loving.
Adopting a less strict and narrow-minded approach than Mary, George Sr. is capable of finding middle ground with his offspring, while still teaching them values and principles. He struggles to understand Sheldon, but is still fiercely encouraging, even siding with the boy against Mary in the matter of college. George Sr.'s eventual future looms largely over the show, and it's one of the things that fans are certainly not looking forward to.
Missy Cooper
Sassy, likable, and intelligent in her own way, Missy is easily the breakout character of the show. A witty, confident and spontaneous young girl who provides a nice contrast to Sheldon's automaton qualities and Georgie's traditional teenager antics.
While Missy's future in TBBT is quite unfair, considering she shows so much promise in Young Sheldon, the character is still enjoyable to watch. She steals nearly every scene she's in, especially when paired with Meemaw, and her one-liners provide the show with a lot of its humor.