The first season of Dynasty, an American television series based on the 1980s prime time soap opera of the same name, originally aired in the United States on The CW from October 11, 2017 through May 11, 2018. The season was produced by CBS Television Studios, with Sallie Patrick as showrunner and executive producer alongside executive producers Josh Schwartz and Stephanie Savage. The pilot, which was announced in September 2016, was ordered to series in May 2017. On November 8, 2017, The CW picked up Dynasty for a full season of 22 episodes. On April 2, 2018, The CW renewed the series for a second season.

Season one stars Elizabeth Gillies as heiress Fallon Carrington, Grant Show as her billionaire father Blake Carrington, Nathalie Kelley as Blake's new wife Cristal, and James Mackay as Fallon's brother Steven, with Robert Christopher Riley as Michael Culhane, Sam Adegoke as Jeff Colby, Rafael de la Fuente as Sam Jones, and Alan Dale as Joseph Anders. Notable recurring characters introduced in season one include Claudia Blaisdel (Brianna Brown); Monica (Wakeema Hollis); Cesil Colby (Hakeem Kae-Kazim); Liam Ridley (Adam Huber); Iris Machado (Elena Tovar); Alejandro Raya (Luis Fernández); Ted Dinard (Michael Patrick Lane); Melissa Daniels (Kelly Rutherford); Hank Sullivan (Brent Antonello); and Alexis Carrington (Nicollette Sheridan).

Dynasty begins with heiress Fallon Carrington unhappy to find her billionaire father Blake engaged to Cristal, a rival employee at the family company. When Fallon's machinations to separate the couple backfire and cost her a promotion, she allies with Blake's nemesis and former employee, Jeff Colby, and strikes out on her own. Meanwhile, the arrival of Cristal's opportunistic nephew Sam—who becomes romantically involved with Fallon's wayward brother Steven—threatens to expose her shady past. The Carringtons form a united front in the wake of the suspicious death of Cristal's former lover Matthew, but things at the mansion do not remain harmonious for long. Blake's manipulations put him at odds with Cristal and his children, while the rivalry between Fallon and Cristal cools. Tired of waiting around for Fallon to take him seriously, Michael begins to date someone else, which only intensifies Fallon's feelings for him but drives her into Jeff's arms. Matthew's pregnant widow Claudia convalesces at the mansion with a hidden agenda, and Cristal's past comes back to haunt her in the form of her sister Iris, and Sam's father, Alejandro. Steven and Sam's on-again, off-again relationship is complicated by Sam's criminal tendencies and Steven's unstable ex-boyfriend, Ted. Jeff's partnership with Fallon is revealed to be a means for him to destroy the Carringtons for what Blake did to Jeff's father, Cesil. Fallon enlists Michael and Cristal to help her turn the tables on the Colbys, and she manages to neutralize Jeff and secure a percentage of his company. Blake's ex-wife Alexis—Steven and Fallon's mother—returns, purportedly to reconnect with her children but in fact angling for a piece of the Carrington fortune. Alexis arranges for her lover to pose as her and Blake's kidnapped son Adam, and reveals to Jeff and Monica that their mother is Blake's half-sister. Fallon ousts Blake as CEO of Carrington Atlantic just as the Colbys force a sale of the company. At Steven and Sam's wedding, an unhinged Claudia appears and shoots Cristal. Blake, Fallon, and Sam escape a fire in the stable house, but Steven, Michael, Alexis, and Cristal remain trapped inside.

The reboot updates several elements from the 1980s original, including moving the setting from Denver, Colorado to Atlanta, Georgia; making Steven's homosexuality a nonissue to Blake; and changing gold digger Sammy Jo from a woman to a gay man. Additionally, in the new series, both Blake's new wife and her nephew are Hispanic, and both chauffeur Michael Culhane and the Colby family are African-American.

In September 2016, it was announced that a reboot of the 1980s prime time soap opera Dynasty was in development at The CW, co-written by Josh Schwartz, Stephanie Savage, and Sallie Patrick. The show received a 13-episode a first season order on May 10, 2017. A preview trailer was released on May 18, 2017. On November 8, 2017, the series received a back nine order for a full season of 22 episodes.

Nathalie Kelley was cast as Cristal in January 2017, followed by Elizabeth Gillies as Fallon, Sam Adegoke as playboy Jeff Colby, and Robert Christopher Riley as Blake's chauffeur Michael Culhane in February. Next cast were Grant Show as Fallon's father Blake Carrington, and Rafael de la Fuente as Sam Jones, a gay male version of the original series' Sammy Jo Carrington, in March. The remaining main cast members are James Mackay as Fallon's gay brother Steven, and Alan Dale as Carrington majordomo Anders, Additional recurring performers include Nick Wechsler as Cristal's ex-lover Matthew Blaisdel, Brianna Brown as Matthew's wife Claudia, and Wakeema Hollis as Jeff's sister Monica Colby. In November 2017, Nicollette Sheridan was cast in the role of Blake's ex-wife Alexis Carrington. Other guest stars include Elena Tovar as Iris Machado, Cristal's sister and Sam's mother, Bill Smitrovich as Thomas Carrington, Blake's estranged father, and Hakeem Kae-Kazim as Cesil Colby, Jeff and Monica's father.

In June 2018, Kelley told E! News that she would not be returning for season two. She said in 2020 that she had been surprised to get the call that she would not be returning to the series, and explained:

I think I wasn't up to the challenge of a nighttime soap. I wasn't prepared for that genre. It wasn't something I had experience in. I didn't know too many actresses who can hold a candle to the wonderful Elizabeth Gillies (Fallon), who absolutely nails that tone and that genre ... I was challenged ... I didn't dig as deep as I could have. I felt limited and I felt stuck. At the same time, the writing was boxing me in a little bit. And I think the best thing they felt they could do is start afresh.