Linda Gray was fired from Dallas after begging the executives to give her a chance to direct like Larry Hagman and Patrick Duffy. However, Larry Hagman threatened to leave the show because he didn't feel they could have JR without Sue Ellen.
The house used as the "Southfork Ranch" house was an actual Texas residence, owned by Joe R. Duncan, or J.R. Duncan. When the show became popular, tourists from all over the world visited the house day and night. The Duncan family was forced to sell the house and it is now a museum devoted to the show.
When Steve Kanaly was talking about leaving the show due to his character's lack of development, it was Larry Hagman who came up with the idea to make the Ray Krebs character the illegitimate son of Jock Ewing in order to get Kanaly to stay
Originally, the show was intended as a starring vehicle for Victoria Principal due to the fact that Pam would act as a buffer between the Ewings and the Barnses and J.R. would have been more of a supporting character. However, the producers were so impressed by Larry Hagman's portrayal of the immoral J.R. that he immediately was bumped up to be the show's main character.
Originally, Linda Gray's Sue Ellen really didn't have a part, so it was up to her and Larry Hagman to improvise their scenes in the background. Fortunately, Leonard Katzman and others saw their work in the dailies of the episodes and Sue Ellen's character was fleshed out.
Spinoff show Knots Landing (1979) was actually created first, but the producers were unable to sell it. They developed Dallas instead and when that became a success, and the network asked for a spinoff, they were able to dust off the Knots Landing idea.
In May 1981, Delta Burke landed the role of Katherine Wentworth but she was forced to turn down the part because she was contractually obligated to the then-yet-to-be-picked-up series Filthy Rich (1982), which was a spoof of "Dallas".
Producers originally planned to bring back Jock Ewing's character, but fans were against having anyone play Jock Ewing except Jim Davis. Steve Forrest appeared on the show as Wes Parmalee, claiming to be Jock Ewing, but it was revealed that he was not.
Several actors including Charlene Tilton and Jim Davis were filmed firing the gun that shot J.R before it was decided who would be the shooter. The gun is on display at the real Southfork Ranch site in Dallas.
In several of the early episodes of the series, Lucy and Ray were often portrayed as lovers. However, when it became revealed that Ray was Jock's illegitimate son, his affair with Lucy was never mentioned again.
Barbara Bel Geddes is only nine years older than Larry Hagman, though they played mother and son. Hagman is 18 years older than Patrick Duffy, who played his younger brother, though we assume them to be only a few years apart in age.
Jenilee Harrison has the distinction of playing the only character to be killed off twice. Jamie Ewing Barnes was killed off the first time in the last episode of the "Dream Season" when she was blown up in her brother's car. The second time came midway through the next season, when she was killed while rock climbing in Mexico. Though the second death didn't occur on camera.
When Patrick Duffy was asked to return to the show in 1986, his wife told him that the only way it could happen is if his character had actually died in a dream. This led the producers to decide that Bobby Ewing's death (in addition to the entire 1985-86 season) was just a figment of Pam Ewing's imagination.
Morgan Fairchild played Jenna Wade, Bobby's childhood sweetheart, in a 1978 episode. When Jenna was seen again for two episodes in 1980, she was played by Francine Tacker as Fairchild was busy working on her own series Flamingo Road (1980). In 1983, with Flamingo Road now canceled, the producers approached Fairchild to reprise the role but she declined feeling that she did not want to return to a small role. However, the producers decided to recast the role with Priscilla Presley and the character became a series regular for five years. Fairchild later claimed that her mother never forgave her for turning down a role in her favorite soap.
Barbara Bel Geddes was living in New York when cast for the series. Throughout the making of the series, Bel Geddes would fly home to New York and back every weekend and on other breaks to be with her family.
Several references were made during the show's run about Clayton Farlow having a past history of singing. Of course, Howard Keel, the actor who portrayed Clayton, was famous for his powerful bass-baritone singing voice.
Barbara Bel Geddes left the show in 1984 due to the producers not agreeing to her demands for a pay rise, and Donna Reed took her place the following season. When Bel Geddes decided to return in 1985, Reed was fired. Reed sued the producers of the show for breach of contract, who settled with her for an undisclosed sum of money. Ironically, Reed died (of cancer) in January 1986, mere months after she left the show which meant she would not have been able to continue for the duration of her contract anyway.
Barbara Bel Geddes appeared in all the episodes of the series, for her first six 1/2 seasons, missing 2, also, 1/3 due to her March 1983 quadruple by-pass heart surgery, allowing her to recover the following year, at the time Donna Reed replaced her and got fired, before returning to Bel Geddes's role for the 1985-86 season before her second departure at the end of the 1989-90 season, where she appeared in all the episodes for 5 more seasons, missing 7, for a total of 280 of the 357 episodes, and almost stayed through the entire run.
In Season 10, JR attempts to weaken OPEC's influence over the price of oil by hiring a group of mercenaries to blow up several oil fields in the Middle East. This storyline is loosely based on Texas businessman Ross Perot's mission to rescue American hostages in Iran in 1979.
Patrick Duffy had wanted the lead role in the 1986 series Heart of the City (1986). When Robert Desiderio was given the part (with a young Christina Applegate playing his daughter), Duffy decided to return to Dallas. Heart of the City lasted only 13 episodes while Dallas remained on the air for several more seasons. Desiderio later appeared in a recurring role in the Dallas spin-off, Knots Landing (1979).
Victoria Principal said in an interview that she left Dallas because she was unhappy with the show's writing. She also said that Lorimar offered her a huge sum of money to remain on the show, and that sum would have made her the highest paid actress on television at that time but she declined their offer. Other sources claim it was over a salary dispute, in which she wanted more money than the show's budget could afford to pay her.