Sherlock Holmes is a 2009 period mystery action film starring Robert Downey Jr. as the character of the same name created by Sir Arthur Conan Doyle. The film was directed by Guy Ritchie and produced by Joel Silver, Lionel Wigram, Susan Downey, and Dan Lin. The screenplay written by Michael Robert Johnson, Anthony Peckham, and Simon Kinberg was developed from a story by Wigram and Johnson. In addition to Downey Jr. as Holmes, Jude Law portrays Dr. John Watson. The film, set in 1890, follows eccentric detective Holmes and his companion Watson attempting to foil a mysticist's plot to gain control of Britain by seemingly supernatural means. Rachel McAdams stars as Holmes' former adversary Irene Adler and Mark Strong portrays villain Lord Henry Blackwood.

Robert John Downey Jr. is an American actor. His films as a leading actor have grossed over $14 billion worldwide, making him one of the highest-grossing actors of all time. Downey's career has been characterized by some early success, a period of drug-related problems and run-ins with the law, and a surge in popular and commercial success in the 2000s. In 2008, Downey was named by Time magazine as one of the 100 most influential people in the world. From 2013 to 2015, he was listed by Forbes as Hollywood's highest-paid actor.