Superior Donuts is a comedy about the owner of a small donut shop that's located in a quickly gentrifying Chicago neighborhood. Arthur is a gruff, to the point Chicagoan who refuses to sell newfangled cronuts and macchiatos or renovate his dated shop that hasn't changed since it opened in 1969. That all changes when enterprising go-getter Franco fast talks his way into Arthur's life as his new (and only) employee, and convinces him that he can bring the shop – and Arthur – into the 21st century. Arthur's supportive regulars include loyal patron Randy, a cop whose late father was Arthur's best friend; her overeager rookie partner, James; Tush, a colorful customer who uses the shop counter as a makeshift office, where he keeps tabs on a variety of odd jobs via fax machine; Maya, a privileged grad-school student working on her Ph. D; and Sweatpants, Franco's longtime friend who's willing to dress as a donut to help drum up more business. Looking to cash in on the urban renewal is Arthur's over-caffeinated neighbor, aspiring real estate capitalist Fawz, who pushes Arthur on a daily basis to sell the building to him. With his business in jeopardy, Arthur grudgingly realizes that he had better embrace the change around him and that Franco could be exactly what he – and the donut shop – need to thrive.
Arthur's business is threatened when Sofia, an ambitious young entrepreneur, parks her organic food truck in front of the donut shop, becoming a hit with his customers and catching Franco's eye. Also, Franco grows frustrated trying to follow his dream of going to college.
When a video surfaces of Randy being aggressive during a traffic stop, Franco begins to question her capabilities as a police officer. To prove that Randy is a good cop, Arthur agrees to Franco's request to tail her while she's on duty, and the night takes a dramatic turn.
When Franco decides to host an orphans' Thanksgiving at the donut shop, he encourages Arthur to invite his daughter, Lucy, but Arthur will only agree if Franco invites his own estranged family member, his father, Reggie.
After a fed-up Franco fires Arthur's longtime flour supplier for making offensive comments, Franco vows to find a more principled replacement, but the task proves more challenging than expected. Also, Randy reluctantly agrees to let Tush crash at her place when he rents his apartment during Pride Weekend to make extra cash.
In the spirit of the season, Franco convinces Arthur and the rest of the gang to help John, a homeless man who falls ill at the donut shop, get back on his feet. Also, Tush and Sweatpants compete to be the more popular Santa.
When Arthur suddenly decides to run against Fawz in a local election, his campaign manager, Franco, tries to help his boss bring home a win. Also, Tush and Randy realize they crossed paths long before the donut shop, and the encounter was hardly sweet.
Faced with art school expenses, Franco gives Sweatpants a choice: find a job to help pay their rent or find a new place to live. Also, Tush and Fawz go to great lengths to help Randy build a social media presence that will inspire envy in her ex.
Convinced his first art-school assignment is a masterpiece, Franco is shocked when he receives a below-average grade and his unimpressed professor asks for a do-over. Also, Arthur becomes determined to discover the true identity of the customer who dared give his shop's coffee a negative online review