Chuck and Buck are childhood best friends whose lives have taken very different paths. While Chuck moved away and now has a real life, Buck stayed behind and developed a dangerous fixation—on Chuck's life.
| Actor | Role |
|---|---|
 Mike WhiteBuck | Buck |
 Chris WeitzChuck | Chuck |
 Lupe OntiverosBeverly | Beverly |
| BBeth ColtCarlyn | Carlyn |
 Paul WeitzSam | Sam |
 Maya RudolphJamila | Jamila |
| MMary WigmoreDiane | Diane |
 Paul SandBarry | Barry |
| GGino BuccolaTommy | Tommy |
| AAnnette MurphyTommy's Mom | Tommy's Mom |
 Glory SimonWitch | Witch |
| DDouglas KiefferMark | Mark |
| JJonathan BrownJake | Jake |
| RRuthie BramDorothy | Dorothy |
| GGiovanni GiecoScarecrow | Scarecrow |
| TT.J. WilkinsTheater Kid | Theater Kid |
| EEzra PughTheater Kid | Theater Kid |
| EErin EspinozaTheater Kid | Theater Kid |
| MMegan McCawTheater Kid | Theater Kid |
 Linda LichterBank Teller | Bank Teller |
| MMeredith TuckerJolie | Jolie |
 Zak PennJosh Weintraub | Josh Weintraub |
| TTony MaxwellSelf | Self |
| VVince DuffySelf | Self |
| DDana BarattaMelissa Booth | Melissa Booth |
| PPamela GordonBuck's Mom | Buck's Mom |
| JJosephina J. RochaPilar | Pilar |
| JJesse Lee ThomasYoung Chuck (Photos) | Young Chuck (Photos) |
| CCaleb WilsonYoung Chuck (Film) | Young Chuck (Film) |
| NNathaniel OldermanYoung Buck | Young Buck |