27 Dresses centres around Jane (Ketherine Heigl), an idealistic, romantic and completely selfless woman. Jane has always been good at taking care of others, but not so much in looking after herself. Her entire life has been about making people happy - and she has a closet full of 27 bridesmaid dresses to prove it. One memorable evening, Jane manages to shuttle between wedding receptions in Manhattan and Brooklyn, a feat witnessed by Kevin (James Marsden), a newspaper reporter who realizes that a story about this wedding junkie is his ticket off the newspaper's bridal beat.

Jane finds Kevin's cynicism counter to everything she holds dear - namely weddings, and the two lock horns. Further complicating Jane's once perfectly-ordered life is the arrival of younger sister Tess (Malin Akerman). Tess immediately captures the heart of Jane's boss, George (Edward Burns). Tess enlists her always-accommodating sister to plan yet another wedding - Tess and George's - but Jane's feelings for George lead to shocking revelations... and maybe the beginning of a new life.