Lucifer is a 2019 Indian Malayalam-language political action thriller film directed by Prithviraj Sukumaran, in his directorial debut, and written by Murali Gopy. It is the first instalment in the Lucifer Franchise. It is produced by Antony Perumbavoor through Aashirvad Cinemas. It stars Mohanlal along with a huge supporting cast consisting of Vivek Oberoi, Manju Warrier, Prithviraj Sukumaran, Tovino Thomas, Indrajith Sukumaran, Saniya Iyappan, Saikumar, Baiju Santhosh, Kalabhavan Shajohn, Sachin Khedekar, and Fazil. The film's music was composed by Deepak Dev, with the cinematography and editing handled by Sujith Vaassudev and Samjith Mohammed respectively.

Development for the film began in 2016 when Gopy pitched the story to Prithviraj on the sets of Tiyaan. The title of the film was taken from a shelved project directed by Rajesh Pillai, which was also written by Gopy but with a different story. Pre-production began in 2017 with Gopy completing the final draft of the screenplay in February 2018. Principal photography began in July that year and was completed in January 2019, with filming taking place across Kerala in Thiruvananthapuram, Idukki, Ernakulam, and Kollam, along with schedules in Mumbai, Bangalore, Lakshadweep, and Russia.

Lucifer was released in theatres worldwide on 28 March 2019. It was also dubbed and released in Hindi, Tamil, and Telugu. The film broke many box office records for a Malayalam film, crossing the ₹50 crore (US$5.8 million) mark in four days, ₹100 crore (US$12 million) mark in eight days, becoming the fastest Malayalam film to reach all these milestones. Lucifer was the first Malayalam film to earn more than ₹200 crore, including its box office collections and the earnings from the sale of its satellite rights and digital streaming rights in other languages. It is currently the eighth highest-grossing Malayalam film. A sequel titled L2: Empuraan (2025), was released on 27 March 2025. It will then be followed by another sequel called L3: Azrael.