In the outrageous comedy," Wedding Crashers", divorce mediators John Beckwith (Owen Wilson) and Jeremy Grey (Vince Vaughn) are business partners and life-long friends who share one truly unique springtime hobby…crashing weddings! Whatever the ethnicity of the wedding party – Jewish, Italian, Irish, Chinese, Hindu – the charismatic and charming duo always have clever back stories for inquisitive guests and inevitably become the hit of every reception, where they strictly adhere to their proven "rules of wedding crashing" to meet and pick up women aroused by the very thought of marriage.
At the tail end of another successful season of toasting brides and grooms, Jeremy learns that the daughter of Treasury Secretary William Cleary (Christopher Walken) and his wife Kathleen (Jane Seymour) is getting married in what is sure to be the Washington, D. C. social event of the year. After infiltrating the lavish affair, John and Jeremy quickly set their sights on bridesmaids Claire (Rachel McAdams) and Gloria (Isla Fisher) Cleary.
With the lavish reception in full swing, Jeremy works his game plan to perfection in seducing Gloria, but John's flirtatious banter with Claire is unexpectedly impeded by her pompous, Ivy League boyfriend Sack (Bradley Cooper). Having uncharacteristically fallen hard and fast for Claire, John convinces a resistant Jeremy to bend the crashing rules and accept an invitation to an extended weekend party at the Cleary family compound.
Once at the palatial waterfront estate, John and Jeremy endure a multitude of comical mishaps at the hands of the hysterically dysfunctional members of the Cleary family, but also learn a few unexpected lessons about love and relationships.