Duncan Mayor decides the perfect Christmas present for his terminally ill wife, Suzy, is a ride on a real Ferris wheel, set up in their very own back yard. As a young man, it was the perfect place for a wedding proposal. Now, years later, in order to relive the experience with his wife, Duncan will go to any length to make their fantasy become a reality.
Jane (Anna Faris), a struggling but perpetually stoned actress, has a busy day ahead. She has several important tasks on her list, including buying more marijuana. Even though she already has a good start on the day's planned drug use, she eats her roommate's pot-laced cupcakes and embarks on a series of misadventures all over Los Angeles.
Wonder wheel tells the story of four characters whose lives intertwine amid the hustle and bustle of the Coney Island amusement park in the 1950s: Ginny, an emotionally volatile former actress now working as a waitress in a clam house; Humpty, Ginny's rough-hewn carousel operator husband; Mickey, a handsome young lifeguard who dreams of becoming a playwright; and Carolina, Humpty's long-estranged daughter, who is now hiding out from gangsters at her father's apartment.