A Simple Favor is a 2018 American crime comedy thriller film directed by Paul Feig. Its screenplay by Jessica Sharzer is based on the 2017 novel of the same name by Darcey Bell. It stars Anna Kendrick, Blake Lively, Henry Golding, Andrew Rannells, Linda Cardellini, Rupert Friend, and Jean Smart and follows a small-town vlogger who tries to solve the disappearance of her elegant and mysterious friend.

It was released in the United States on September 14, 2018, by Lionsgate. Critics praised the plot twists, and the performances of Kendrick, Lively and Golding. It grossed $97 million worldwide on a $20 million budget. A sequel is in development, with Kendrick and Lively set to reprise their roles, and Feig returning to direct.

Widowed single mother Stephanie Smothers runs a vlog featuring crafts and recipes for parents. She becomes friends with Emily Nelson, the mother of her son's schoolmate and a PR director for a fashion company, and they exchange confessions over martinis. Stephanie shares that as a teenager, she had sex with her half-brother Chris. Emily is frustrated by the lack of success of her husband, English professor Sean Townsend, and their (well-hidden) poor financial situation. Stephanie has a passion for baking and loves to show off her speciality fruit meringue cakes for her blog.

Stephanie babysits Emily's son while Sean is in London. After two days of Emily not returning calls, she learns from Emily's boss, Dennis Nylon, that she is in Miami. Stephanie calls Sean, who contacts the police. Trying to get to the bottom of Emily's disappearance, she makes missing person flyers using a photo of Emily that she found hidden on her desk.

Detective Summerville reports that Emily lied about flying to Miami, and that her drowned body had been discovered in the lake at a summer camp in Michigan. Stephanie and Sean share their grief and begin a sexual relationship. Summerville reveals to Stephanie that Emily had severe liver damage, a large amount of heroin in her system, and that Sean had recently taken out a $4 million life insurance policy on her.

Stephanie receives an insulting message apparently from Emily about her tryst with her half-brother Chris. She has a flashback of her late husband suspecting her infidelity, possibly leading him to cause the car crash that killed both him and Chris.

Investigating Emily's past, Stephanie meets Diana Hyland, who seems to have been a lover of Emily and who had painted a portrait of her. Diana says that the painting is actually of her muse Claudia, whom she describes as a con artist who disappeared. Her information leads Stephanie to a yearbook that shows Emily to be a girl named Hope McLanden, and who had an identical twin named Faith. Stephanie visits Margaret, the mother of the twins, who explains that at 16, the twins had set fire to the family house, killing their father, and disappeared.

Meanwhile, while Stephanie is away on these investigative trips, Emily surprises Sean by reappearing, and tells him that she plans to collect the insurance money and leave the country. Stephanie later contrives to meet with Emily, who explains that she and her sister indeed started the fire to kill their abusive father.

The sisters fled separately with a plan to reunite later, but Faith didn't turn up as agreed. Emily then built a career and family but then Faith reappeared 14 years later. Now an alcoholic and heroin addict, Faith threatened to turn them both in to the authorities by confessing the patricide unless paid a million dollars by Emily. After assenting to the demand, Emily drowned Faith in the lake (as revealed to the movie audience), but Emily tells Stephanie that Faith committed suicide and that Sean planned the insurance scam.

Emily and Stephanie are both angered by Sean's relationship with the other and decide to frame Sean. He is arrested and released on bail. Stephanie has a change of heart and stages an argument with Sean in front of Emily in order to incriminate her while police-planted microphones are recording the meeting. Stephanie fakes shooting Sean.

Emily, having predicted their ruse and disabled the microphones, confesses her crimes while holding the pair at gunpoint, saying that she will stage their murder-suicide. Shooting Sean in the shoulder, she turns the gun on Stephanie, who reveals that a hidden camera is livestreaming the entire event on her vlog. Emily attempts to escape, only to be hit by a car driven by Stephanie's friend Darren. She is arrested immediately after.

Closing text says that Emily was sentenced to 20 years in prison, Sean's second novel was a bestseller and he became a successful professor at Berkeley, and Stephanie is said to be dating another man and that her vlog has a million followers and is being developed as a TV show and also that she is a part-time private detective. In a mid-credits scene, Emily is seen winning a basketball game in prison.

• Anna Kendrick as Stephanie Smothers
• Blake Lively as Emily Nelson / Hope McLanden and Faith McLanden
  • Nicole Peters & Lauren Peters as Hope McLanden and Faith McLanden (16 years old)
• Henry Golding as Sean Townsend
• Andrew Rannells as Darren
• Linda Cardellini as Diana Hyland
• Dustin Milligan as Chris
• Jean Smart as Margaret McLanden
• Rupert Friend as Dennis Nylon
• Eric Johnson as Davis Smothers
• Bashir Salahuddin as Detective Summerville
• Aparna Nancherla as Sona
• Joshua Satine as Miles Smothers
• Ian Ho as Nicholas “Nicky” Townsend-Nelson
• Kelly McCormack as Stacy
• Sarah Baker as Maryanne Chelkowsky
• Melissa O'Neil as Beth T.A.
• Patti Harrison as Kiko
• Corinne Conley as librarian

The film was released on September 14, 2018.^[9]

In May 2022, a sequel was announced, with Feig returning to direct the film, and Kendrick and Lively set to reprise their roles. Lionsgate will co-produce the film with Amazon MGM Studios.^[18][19] In March 2024, Amazon officially greenlit the sequel, with Golding, Rannells, Salahuddin, Satine, Ho and McCormack also reprising their roles.^[20]