The actress joins Robert Webb and Rufus Hound in the comedy from Calendar Girls makers Nigel Cole and Tim Firth, according to The Hollywood Reporter.
The movie centres on a wedding video filmed as a gift by the best man, which goes disastrously wrong and embarrasses everyone involved.
Punch most recently starred in black comedy Bad Teacher opposite Cameron Diaz and Justin Timberlake.
In July, she admitted that she preferred taking smaller roles instead of lead parts because they offer more variety.
The Hot Fuzz actress will next be seen in the romantic comedy The Giant Mechanical Man.
Watch Digital Spy's Bad Teacher interview with Lucy Punch below: