Mike Flanagan is a prolific writer, director, and editor of feature films and television, and founder of Red Room Pictures. Flanagan entered into an exclusive overall deal with Amazon Studios in 2023 for television projects (after a similar exclusive deal with Netflix lasted from 2018-2022), and has produced feature films for Warner Bros., Universal Pictures, and Netflix, among others. Flanagan is best known for his work in horror films and television series, which has attracted the praise of critics for his focus on character and lack of reliance on jump scares. Stephen King, Quentin Tarantino, and William Friedkin, among others, have praised him.

Flanagan was born in Salem, Massachusetts to Timothy and Laura Flanagan. The family relocated frequently, as Timothy was in the U.S. Coast Guard, and finally settled in Bowie, Maryland. As a child, he would shoot and edit short movies on VHS. This continued as he attended Archbishop Spalding High School in Severn, Maryland, where he was active in the theatre department and the president of the Student Government Association. A graduate of Towson University's Electronic Media and Film department, Mike moved to Los Angeles in 2003 and began working as an editor of sketch comedy shows, reality television, documentary programming and commercials before his Kickstarter-funded breakout feature Absentia (2011) launched his filmmaking career.

Flanagan's films, all of which he directed, wrote, and edited, include Oculus (2013), Hush (2016), Before I Wake (2016), Ouija: Origin of Evil (2016), Gerald's Game (2017), Doctor Sleep (2019), and The Life of Chuck (2024). He also created, directed, and served as showrunner on the series The Haunting of Hill House (2018), The Haunting of Bly Manor (2020), Midnight Mass (2021), the teen horror series The Midnight Club (2022) and The Fall of the House of Usher (2023).

Flanagan has been nominated for dozens of awards for writing, directing and editing, and was presented with the Visionary Award by the Academy of Science Fiction, Fantasy and Horror Films in 2022. He is an active member of the Producers Guild of America, Directors Guild of America, Writers Guild of America West, Motion Picture Editors Guild, and Screen Actors Guild.

Flanagan lives in Los Angeles with his wife, actress Kate Siegel, whom he married in 2016. They have a son and a daughter together, as well as a son from Flanagan's previous relationship with Absentia actress Courtney Bell. He has been sober since 2018, and frequently uses his work to explore themes of addiction, recovery, and empathy.