The series stars Kelsey Grammer as Tom Kane, the mayor of Chicago, who has recently been diagnosed with Lewy body dementia, a degenerative neurological disorder.

[5] A film was discussed to finish the show's storylines,[6] but those plans were cancelled after series creator Farhad Safinia declined to move forward with the project.

[7] As the series commences we follow Tom Kane, the Mayor of Chicago, who has been diagnosed with dementia with Lewy bodies, a degenerative neurological disorder.

His closest advisors, Kitty O'Neill and Ezra Stone, begin to suspect something is wrong with the Mayor but respect the boundary he has erected that precludes asking such questions, though lapses on Kane's part begin to become apparent to others around him, such as the current Illinois governor McCall "Mac" Cullen and The Sentinel's political journalist Sam Miller.

Meanwhile, Kane and his team work behind the scenes to groom State Treasurer Ben Zajac to become the next Governor of Illinois.

[14] Starz later announced that Martin Donovan, Francis Guinan, Rotimi Akinosho, Karen Aldridge, Troy Garity, Ricardo Gutierrez, James Vincent Meredith and Joe Minoso had joined the series as recurring guest stars.

[15] Rotimi Akinosho was cast as Darius, "a muscular drug dealer who's covered in tattoos, but he's smart, well spoken, and cares for his sick uncle".

[15] Karen Aldrige was cast as Dr. Ella Harris, Mayor Kane's neurologist and (initially) the only other person who knows about his current medical condition.

The website's critical consensus states: "A mature drama, Boss constructs political devolution with ease and packs a powerful punch with steamy tales of corruption and sex.

The website's critical consensus states: "Kelsey Grammer alone provides ample reason to watch Boss, but the rest of the stellar supporting cast of wretchedly fascinating, emotionally entangled characters holds viewer attention.