Warren Schmidt (Jack Nicholson), a quiet ex-insurance actuary, is unhappily married to Helen (June Squibb) and brooding over the forthcoming wedding of his daughter Jeannie (Hope Davis) to Randall Hertzel (Dermot Mulroney). Feeling useless after retiring, he sees a television advertisement about a foster program for African children, Plan USA, and decides to sponsor a child. He soon receives an information package with a photo of his foster child, a small Tanzanian boy named Ndugu Umbo, to whom he relates his life in a series of candid, rambling letters. When Helen suddenly dies and he finds love letters to her from his best friend, he is inspired to try to stop the wedding, but standing in his way is Randall's feisty mother Roberta (Kathy Bates), and slowly, he realizes he must make the most of his remaining life