Deadwood is an American Western television series that aired on the premium cable network HBO from March 21, 2004, to August 27, 2006. The series is set in the 1870s in Deadwood, South Dakota, before and after the area's annexation by the Dakota Territory, and charts Deadwood's growth from camp to town. The show was created, produced, and largely written by David Milch. Deadwood features a large ensemble cast headed by Timothy Olyphant and Ian McShane, playing the real-life Deadwood residents Seth Bullock and Al Swearengen, respectively. Many other historical figures appear as characters, including George Crook, Wyatt Earp, E. B. Farnum, George Hearst, Wild Bill Hickok, Calamity Jane, Sol Star, A. W. Merrick, Jack McCall, and Charlie Utter. The plot lines involving these characters include historical truths as well as substantial fictional elements. Milch used actual diaries and newspapers from 1870s Deadwood residents as reference points for characters, events, and the look and feel of the show.

Deadwood received critical acclaim, particularly for Milch's writing and McShane's performance, and is regarded as one of the greatest television shows of all time. It also won eight Emmy Awards (in 28 nominations) and one Golden Globe. TV Guide ranked it #8 on its 2013 list of 60 shows that were "Cancelled Too Soon", while the Writers Guild of America ranked it #32 on their list of the 101 Best Written TV Series. The show was produced by Red Board Productions and Roscoe Productions in association with HBO and Paramount Network Television.

After several years of discussion and pre-production, Deadwood: The Movie began filming in October 2018. The film is set ten years after the end of the third season and premiered on HBO on May 31, 2019.