Dallas was an American prime time soap opera that aired on CBS from April 2, 1978, to May 3, 1991. The series revolved around an affluent and feuding Texas family, the Ewings, who owned the independent oil company Ewing Oil and the cattle-ranching land of Southfork. The series originally focused on the marriage of Bobby Ewing and Pam Ewing, whose families were sworn enemies. As the series progressed, Bobby's elder brother, oil tycoon J. R. Ewing, became the show's breakout character, whose schemes and dirty business became the show's trademark. When the show ended on May 3, 1991, J. R. was the only character to have appeared in every episode.

The show was prominent for its cliffhangers, including the "Who shot J.R.?" mystery. The 1980 episode "Who Done It" remains the second-highest-rated primetime telecast ever. The show also featured a "Dream Season", in which the entirety of season 9 was revealed to have been a dream of Pamela Ewing. After 14 seasons, the series finale "Conundrum" aired in 1991.

The show was mostly an ensemble cast, with Larry Hagman as greedy, scheming oil tycoon J.R. Ewing, stage/screen actress Barbara Bel Geddes as family matriarch Miss Ellie and Western movie actor Jim Davis as Ewing patriarch Jock, his last role before his death in 1981. The series won four Emmy Awards, including a 1980 Outstanding Lead Actress in a Drama Series for Bel Geddes.

With its 357 episodes, Dallas remains one of the longest lasting full-hour prime time dramas in American TV history, behind Gunsmoke (635 episodes), Law & Order: Special Victims Unit (551 episodes as of May 2024), Law & Order (501 episodes as of May 2024), Bonanza (430 episodes), and Grey's Anatomy (428 episodes as of May 2024). Dallas also spawned spin-off series Knots Landing in 1979, which also lasted 14 seasons and a total of 344 episodes.

In 2007, Dallas was included in Time magazine's list of "100 Best TV Shows of All-Time".

The series finale had a cliffhanger that was resolved in the first of two subsequent reunion films: Dallas: J.R. Returns. There was a second film Dallas: War of the Ewings, and a retrospective special Dallas Reunion: The Return to Southfork.

In 2010, TNT announced it had ordered a new, updated continuation of Dallas, ignoring the events of the two reunion films. The revival series, continuing the story of the Ewing family, premiered on TNT on June 13, 2012, and ran for three seasons, ending its run on September 22, 2014.