Mia Dolan (Emma Stone)
An aspiring actress, Mia works as a barista in a coffee shop on the Warner Brothers lot. At the start of the film she's stuck in a traffic jam preparing for an audition, which metaphorically pretty much sums up the situation: she's been stuck, trying to break in to the industry for six years, so far with no success. Her dream began when she was a child in Boulder City, introduced to old movies by her aunt, who was also an actress. Prompted by Sebastian, and after a series of disappointing meetings, Mia decides to write a show for herself, to show what she can do.
Sebastian Wilder (Ryan Gosling)
A pianist for hire when we meet him, Sebastian dreams of owning his own jazz club. So dedicated is he to the idea, he hasn't even unpacked the boxes in his house, saying he will when he has a club to unpack them in. He isn't interested in going on dates or meeting anyone (if they didn't like jazz, what would they have to talk about?) despite his sister's best efforts to introduce him to someone and stop him from living like a hermit. And then he meets Mia. Determined that her talent will be recognized, he encourages her to write a play for herself and drives her to the audition that launches her career. Meanwhile, he veers off course as a pianist in the (albeit successful) band The Messengers. By the end of the film he's realized his dreams and is running a jazz club called Seb's.
Keith (John Legend)
An old friend of Sebastian's from school, Keith is a musician and singer who wants to update jazz and get young people excited about it. We first meet him in a jazz bar, where he tries to persuade Sebastian to join his new band The Messengers. Although he and Sebastian initially disagree about what the music should be like, the band does well with Keith as lead singer.
Laura Wilder (Rosemary DeWitt)
Laura is Sebastian's sister and is frustrated by his way of life. She's firm: there's nothing romantic about not being able to pay the bills, and tries to get him to grow up and earn a steady wage. She's even trying to hook him up with a date—she thinks he lives like a hermit. Her life seems to follow the more conventional path and we see her getting married and then—in the section 'Winter' five years later—we see her with a young child. In Sebastian's eyes she has no respect for jazz or its magic. She doesn't understand his obsession and particularly doesn't understand him hanging around the Van Beek club just to imagine what it could one day be, telling him it's stalker behavior.
Bill (J. K. Simmons)
The manager of Lipton's restaurant, Bill is firm with Sebastian about playing the chosen set list: Christmas songs. When Sebastian doesn't, he is quick to fire him. Bill takes no prisoners and even when Sebastian pleads with him that "it's Christmas," he simply responds: "I see the decorations. Good luck in the New Year."
Carlo (Jason Fuchs)
Mia is introduced to Carlo by her housemate at a pool party. He's a writer or "word builder," as he calls it who's got a lot of "heat." He bores Mia within ten seconds, driving her alone to the bar.
Tracy (Callie Hernandez)
One of Mia's housemates, Tracy persuades Mia to come to a party by promising her she'll put her up for the four things in her inbox that she'd be perfect for—if she joins them.
Alexis (Jessica Rothe)
Another of Mia's housemate and also an actress, she tells Mia they'll make fun of the people at the party together if she joins them. She, like Tracy, is keen to encourage Mia out so that she doesn't sit alone and depressed after her miserable audition.
Greg (Finn Witrock)
Mia's boyfriend before Sebastian, Greg is smart and sophisticated, but to Mia he is fundamentally dull. They have been dating for a month when we meet Mia. When his brother comes to town, Mia joins them at a fancy restaurant where she feels out of place. The brother is smug, interrupts the dinner for a business call and talks about the expensive gadgets he's recently bought, and Mia—unable to stomach it—leaves them to meet Sebastian instead.
Famous actress (Aimée Conn)
Entirely elusive, this role serves to present the difference between where Mia is and where she wants to be. The actress is smart and sophisticated, with huge sunglasses, and she gets driven to the set in a Cadillac: the image of success.
