While trying to make his sister's wedding day go smoothly, Jack finds himself juggling an angry ex-girlfriend, an uninvited guest with a secret, a misplaced sleep sedative, and the girl that got away in alternate versions of the same day.
| Actor | Role |
|---|---|
 Sam ClaflinJack | Jack |
 Olivia MunnDina | Dina |
 Eleanor TomlinsonHayley | Hayley |
 Freida PintoAmanda | Amanda |
 Joel FryBryan | Bryan |
 Jack FarthingMarc | Marc |
 Allan MustafaChaz | Chaz |
 Tim KeySidney | Sidney |
 Aisling BeaRebecca | Rebecca |
 Paolo MazzarelliVitelli | Vitelli |
| TTiziano CaputoRoberto | Roberto |
 Simonetta SolderSophia | Sophia |
 Stefano PattiRoberto's Best Man | Roberto's Best Man |
 Giusi MerliGrandmother | Grandmother |
| FFrancesca RoccoCristina | Cristina |
 Achille BrugniniPriest | Priest |
 Alexander ForsythGreg | Greg |
 Christian HillborgOlof | Olof |
 Penny RyderThe Oracle (voice) | The Oracle (voice) |