Ryan Murphy, a fan of Bette Davis since childhood, interviewed the actress just months before her death in 1989; a planned 20-minute interview stretched to four hours and shaped his characterization of Davis in Feud.

Murphy originally conceived Bette and Joan as a feature film years before it became a TV series, approaching both Susan Sarandon and Jessica Lange for the lead roles at that time.

The eight episodes of Bette and Joan were expanded from a feature-length screenplay called Best Actress, written by Jaffe Cohen and Michael Zam, which Murphy had optioned.

The series was written while Murphy was forming his Half Foundation to promote more women in film and TV production roles, and Bette and Joan featured 15 acting roles for women over 40, with half the episodes directed by women, including actress Helen Hunt.

On June 30, 2017, the day before her 101st birthday, Olivia de Havilland sued the makers of Feud: Bette and Joan for using her likeness without permission and inaccurately portraying her in the show's pseudo-documentary style; the case eventually reached the U.S. Supreme Court, which declined to hear it in January 2019.

The planned second season was initially conceived as Charles and Diana (later retitled Buckingham Palace), focusing on Prince Charles and Princess Diana, with Matthew Goode and Rosamund Pike cast in the lead roles, before the project was scrapped in August 2018.

Before the show's official premiere at the Chinese Theatre in Los Angeles, FX held special screenings of the pilot episode at several gay bars across the United States.

A short commercial for Feud aired during Super Bowl LI as part of its marketing campaign.