Glendale, California, 1931: Mildred Pierce, a young mother with a talent for baking, is left a “grass widow” after throwing her husband, Bert, out of the house. Forced to hunt for work to support herself and her two young daughters, 11-year-old Veda and seven-year-old Ray, Mildred visits an employment agency, only to encounter job opportunities she feels are beneath her. Amidst her job search, she receives dating advice from her friend and neighbor, Lucy Gessler, and begins an unexpected affair with an ex-business partner of her husband’s, Wally Burgan. When Mildred receives a call from the agency regarding an opening as a housekeeper to a wealthy socialite, she reluctantly agrees to meet with her. After cutting the acerbic interview short, Mildred seeks refuge at a local diner, Cristofor’s Café, where fate, and a waitress named Ida, will play a role in shaping her future.

1931: Mildred's business prospects get a boost when she starts selling her homemade pies at the diner. With the help of Wally Burgan, Bert's ex-business partner, she finds a perfect space to launch a chicken-and-pie restaurant as business booms, though her marriage to Bert threatens to short-circuit its financing. After an amicable divorce, Mildred becomes the owner of her own restaurant, but her relationship with her precocious daughter Veda is fraying. On her last day at the diner, Mildred finds unexpected romance when she impulsively joins a handsome customer, Monty Beragon, on a holiday at the Santa Barbara shore. Unfortunately, her happiness is short-lived, as tragedy strikes when the pair returns home.

1931-1933: In the wake of unspeakable tragedy, Mildred moves forward with preparations for her new chicken-and-waffle restaurant. After a slow start on opening night, the restaurant fills to capacity, and Mildred gladly welcomes Ida - her former fellow waitress at the diner - to help manage the frenzy. Among the guests is Monty, who wastes no time reacquainting himself with Mildred, and impressing Veda with his refined stature. At Montyʼs suggestion, Mildred hires a new piano teacher for Veda, but is unable to buy her a new piano when the repeal of prohibition forces her to add a bar to the restaurant. As Veda grows resentful, Mildred chafes at the indolent Monty and his extravagant lifestyle, culminating in an emotional New Year's Eve faceoff.

Four years later, 1937-1938: After expanding her Glendale eatery to include a Beverly Hills luncheonette, Mildred and Lucy, her best friend and junior business partner, eye Laguna Beach as the site for a new oceanfront restaurant, with a seafood-and-steak menu. However, Mildredʼs business success is tempered by a growing rift with Veda, who despairs when her longtime piano teacher dies and a prospective replacement, well-known conductor Carlo Treviso, is less than complimentary. Stung by rejection, Veda ends up in the company of society loafer Sammy Forrester, whose mother surprises Mildred with shocking allegations about their children. When Mildred confronts Veda, an emotional argument ensues and Mildred angrily throws her out of the house. After months with no communication between the two, Bert tells Mildred about Vedaʼs success as a singer on the radio. Listening to Veda sing, Mildred is pained by her daughterʼs estrangement, and is determined to win her back.

1938-1940: Though her initial attempts to reconcile with Veda fail, Mildred does end up reconnecting with Monty, who is only too happy to have his newly affluent lover purchase his family estate in Pasadena. Meanwhile, Vedaʼs career as a coloratura soprano takes off under the tutelage of Carlo Treviso and a new manager. Although mother and daughter finally make up on the occasion of Mildredʼs wedding to Monty, all is not well. After a stream of financial indulgences, Mildred ends up in a bind when the Laguna restaurant slumps, and the disloyal Wally threatens legal action on behalf of her creditors. Urged by Bert to ask the successful Veda for a loan, Mildred returns home to a shocking revelation that will change her life forever.