The movie begins with Toula, a woman who is struggling with her life. Her travel agency is closed and she is also facing problems with her married life. Her husband, Ian, is the principal in a school. Their love life is in trouble as Ian feels that Toula has no time for her. Their teenage daughter, Paris is also rebellious and clashes with the traditions of the Greeks.
A family secret comes to light and it shocks everyone. Toula’s father, Gus comes to know that his marriage certificate doesn’t have the signature of the priest and so, he decides to remarry Maria. Maria ignores this idea at the start, but then she decides to marry him if he asks her hand properly. With the idea of marrying again after fifty years of their marriage, Maria decides to have a wedding, that she always dreamt of and this calls for a Big fat Greek wedding.