The Big Bang Theory is a popular sitcom running from 2007 to 2019. The Big Bang Theory follows four core characters - a quartet of scientist friends and their misadventures in the workplace, their many beloved fandoms and most of all, the world of dating and love. Even if they have many mishaps and blunders, these four guys are all incredibly smart, and they've earned those degrees.
Many other characters in The Big Bang Theory are impressively smart too. As the cast of characters grew, new scientists arrived to rival the four main guys in academia, including their future wives and new best friends. These major characters can be roughly sorted according to intelligence, measured by their college degrees, success in their fields of study, resourcefulness, clever thinking and more.
10 Stuart Bloom Runs A Comic Shop
The four main guys all love comic books, especially Marvel and DC titles, and they regularly visit the local comic book shop to pick up the latest issues. The owner is their friend Stuart Bloom, a meek and unassertive fellow who doesn't have much luck in his dating life.
Stuart may not have a Ph.D., but he still has the business acumen to keep his shop doors open, and he sometimes tricks the four main guys into buying items they don't intend to purchase, showing his clever side. Stuart is smarter than Sheldon gives him credit for.
9 Penny Hofstadter Has Become Successful
At first, the charming girl next door Penny embodied the negative "dumb blonde" stereotype. Penny was The Big Bang Theory's least successful and least intelligent character, though she did have charisma and excellent acting by actress Kaley Cuoco on her side.
Fortunately, The Big Bang Theory eventually gave Penny more to do. She continued to dispense empathetic folk wisdom and clever insights to the four guys, and she later started a successful career in the medical field. Penny worked hard and learned much, which helped bridge the gap between her and her genius friends.
8 Leslie Winkle Butted Heads With Sheldon
Leslie Winkle was a mainstay in The Big Bang Theory during its early years, and she was a minor rival for Sheldon Cooper. Leslie works at CalTech, just like the four main guys, and she can handle complex equations and theories just as well as they can. During Leslie's best moment, she actually corrected Sheldon on his work.
That was an exception, though, and Leslie has few other accomplishments to her name. She is successful and practical, but she never reached the same heights as the other scientist main characters, so it can be inferred that she's not quite on their level.
7 Bernadette Rostenkowski-Wolowitz Is A Fine Microbiologist
Bernadette Rostenkowski, when she first appeared in Big Bang, was a waitress at the Cheesecake Factory alongside Penny, a friend of hers. Soon enough, Bernadette obtained her Ph.D. and launched a career in her intended field, microbiology. She's had a few mishaps in the lab, but nothing too serious.
Bernadette is known for her mature, practical and motherly personality, and she takes her career and family quite seriously. It became clear through dialogue that she is a gutsy and innovative worker in her field, and no doubt her employers are deeply impressed.
6 Amy Farrah Fowler Likes Monkeys & Chaucer
Amy Farrah Fowler made a cameo at the end of season 3, but she truly joined the main cast of Big Bang in season 4, as Sheldon's dry and awkward pseudo-girlfriend. Amy is a neurologist with a Ph.D and a love of classic literature, which shows how flexible and curious her mind can be.
Amy is a skilled scientist both on paper and in the lab, and she can dissect delicate brain tissue samples with a steady hand. Like Bernadette, Amy is a bold and innovative worker in her field, though this might backfire on her once in awhile. Still, curiosity is a scientist's best tool.
5 Howard Wolowitz Can Build Anything
Howard Wolowitz is one of the four main guys of The Big Bang Theory, and he's been a savvy and enthusiastic engineer ever since the beginning. Howard puts his Master's degree to good use, and regularly builds and tinkers with all kinds of gadgets, from robot arms to battle bots.
Howard even became a payload specialist on the ISS, and he became a trained astronaut to work aboard that station. Howard's inventions might sometimes blow up in his face, but he can get back on his feet and resume work before long. He's not one to give up, even when Sheldon mocks and insults him.
4 Priya Koothrappali Can Practice Law In Three Countries
Priya Koothrappali is Rajesh's younger sister, and while she is not an astronomer or physicist, she brilliant as an attorney, much to Sheldon's chagrin. Priya graduated from Oxford at the top of her class, according to Leonard, and that speaks volumes about Priya's razor-sharp wits and intellect.
Priya got a chance to show off her formidable legal skills when she reviewed the roommate agreement and found multiple faults in it. She amazed everyone when she outmaneuvered Sheldon with his own document in The Big Bang Theory. As Leonard added, Priya can practice law in three different countries. That's impressive.
3 Raj Koothrappali Is A Dedicated Astronomer
Rajesh is another of the four main guys, and he graduated from Cambridge with a Ph.D. in astronomy, which is truly impressive. He didn't stay in the UK or return to India, though - Raj relocated to Pasadena, California, and soon met Howard. Then he met Leonard and Sheldon, and befriended both.
Raj is a skilled and passionate astronomer, and he can handle advanced equations like it's nobody's business. He is roughly as smart as his sister Priya, but his imagination and areas of study are broader than hers, meaning he can be ranked slightly higher than her in overall intelligence and creativity.
2 Leonard Hofstadter Comes From A Family Of Scientists
Leonard is yet another of the four main guys in The Big Bang Theory, and definitely the second-smartest of them. Leonard didn't like it, but he grew up in a whole family of cold and calculating scientists, which helped ensure he grew up to be a scientist too. In particular, Leonard studies particle physics.
Leonard is equally adapt at handling advanced equations and high-tech lab equipment, and though he has a reputation for borrowing other people's work. Leonard is brilliant and flexible in his thinking, and he can handle a wide variety of academic subjects with ease. He's also fairly clever in everyday life, and sometimes pranks Sheldon.
1 Sheldon Cooper Towers Above Everyone Else
Dr. Sheldon Lee Cooper may be obnoxious, stubborn, physically frail and oddly gullible at times, but there's no denying that he is The Big Theory's smartest character by a comfortable margin. He has two Ph.D.'s and a Master's degree, to begin with, and he has a photographic memory and a keen eye for details and patterns as well.
In addition, Sheldon was a boy genius, tackling grad school-level problems and formulas before he even turned 10, something that not even his best friends could have done. Sheldon is also diabolically clever as a prankster and schemer at times, and he can recall absolutely any detail or trivia bit to refute someone else's argument or illustrate a point. Sheldon may slip up sometimes, but as a whole, he can school anyone else in The Big Bang Theory.