Dev.D is a 2009 Indian Hindi-language romantic drama film written and directed by Anurag Kashyap. It is a modern-day adaptation of Sarat Chandra Chattopadhyay's 1917 Bengali novel, Devdas. The film stars Abhay Deol, Mahie Gill and Kalki Koechlin in lead roles. The film is set in modern-day Punjab and Delhi, and follows Devendra Singh "Dev" Dhillon (Abhay Deol), a privileged young man who descends into alcohol and drug addiction after a failed relationship with his childhood love Parminder "Paro" Kaur (Mahie Gill), eventually forming an unexpected bond with Chanda (Kalki Koechlin), an escort navigating her own emotional trauma.

The idea for Dev.D was developed by Anurag Kashyap and Abhay Deol, drawing on real-life incidents, including the 2004 Delhi Public School MMS scandal and a high-profile hit-and-run case. Principal photography took place in Delhi and Punjab, with visually distinct palettes for each character’s arc.

The film was released on 6 February 2009 to strong critical acclaim for its unconventional storytelling, visual style, and music. It had a modest box office performance, earning ₹21.5 crore domestically against a small budget, and was declared a hit. Over time, Dev.D attained cult status and is now considered a landmark in Indian independent cinema. A tie-in mobile video game based on the film was released by UTV Indiagames.

The film’s soundtrack was composed by Amit Trivedi and featured 18 songs spanning rock, folk, jazz, and electronic influences. It was praised for its innovation and seamless integration with the narrative. Trivedi received the National Film Award For The Best Music Direction and the Filmfare Award for Best Music Director for his work on the album.

The film is divided into three parts from the point of view of the main characters.

Paro is a young, idealistic middle-class girl living in Punjab. Her childhood sweetheart is Dev, the son of a rich businessman. Paro cares for him immensely, and fully expects a future with him. Dev constantly takes Paro's love and affection for granted. He grows up to be spoiled, arrogant, and lazy, which causes his father to send him to London to complete his education. While separated by distance, Paro and Dev's youthful love only blossoms more, despite Dev growing increasingly egotistical and entitled. After finishing his studies, Dev returns to Chandigarh and meets Paro, and they rekindle their romance. After some time, Dev overhears scandalous rumours about Paro, concerning her reputation and sexual history, which he immediately believes despite no evidence. Paro is shocked at his chauvinist attitude, even after she claims innocence. Dev hypocritically passes judgement onto Paro and does not approve of the things that he has heard. Paro turns her back on him when she hears him insult her and rashly agrees to marry a man of her parents' choice. On her wedding day, Dev learns that the rumors were false but his ego doesn't let him accept his mistake, and he lets Paro marry Bhuvan.

Leni is a Delhi student of half-European descent. A date with her much older boyfriend turns sexual and lands Leni in an MMS sex scandal. The incident becomes public knowledge after the video is widely circulated. Her father commits suicide out of shame and disgust, and Leni's family decides to send her to live in a small rural town. Refusing to live a life of shame and ridicule, she returns to Delhi where she works as a prostitute at night, while continuing with her studies during the day. She adopts the name 'Chanda' or 'Chandramukhi' for her profession, after she is seen watching Sanjay Leela Bhansali's adaptation of Devdas on TV. Her 'foreign' looks mean her services are reserved for the highest-paying customers, and she finds some dignity and independence in the new way of living. One night, an inebriated, half-conscious customer is brought to her room, who turns out to be Dev. She falls in love with him, even though Dev is still in love with Paro.

Dev, tormented by Paro's wedding, has been seeking refuge in alcohol and drugs. He meets a pimp named Chunni, who after a drinking relay, leads him to Chanda. He finds some solace with Chanda but is unable to forget Paro. While in a drug-fueled haze, he calls Paro's husband in the middle of the night. Paro visits him at the cheap lodge where he is staying, where she shows her love by taking care of Dev but spurns his attempts at physical intimacy. Their reunion ultimately ends on a bitter note and Paro returns to her married life. Dev resolves to go back to Chanda and they fall in love, but confronted by the reality of her profession, he abandons her too. He resumes his destructive lifestyle of alcohol, drugs, and reckless behaviour, culminating in killing seven people in a drunk driving incident. His father dies from shock at the news. Months later, after his life has completely fallen apart and hit an all-time low, Dev attempts to pick up the pieces. He seeks Chanda once again and, with her help, sets out to start life afresh and better himself.