The show's creator and executive producer Josh Berman approached Serena Williams to come on board for Season 4 when he found out she was a fan of the show. The writers then wrote a part specifically for her.
Rosie O'Donnell (Judge Madeline Summers) and Brooke Elliot (Jane/Deb) have worked together before. O'Donnell was the producer of the 2003 Broadway musical Taboo, in which Elliot was a featured performer.
Even though the background setting for Drop Dead Diva is the Millennium Biltmore Hotel in Los Angeles, California, the series was filmed on location in Peachtree City, Georgia, and Senoia, Georgia, with principal photography taking place in a studio contained in a large hangar at the Atlanta Regional Airport, and outdoor locations shot around the town. Filming originally took place in Georgia for tax incentives.
The trivia items below may give away important plot points.
Ben Feldman was never credited as a regular cast member, nor even in the first three season when Fred was a regular character. He went always by "(special) guest star". Regular cast members Margaret Cho, Jackson Hurst and Kate Levering were credited in all 78 episodes, despite being absent from some of them for different reasons.
As with many TV shows, the set decoration for Harrison and Parker Law Firm is different at the pilot than from the rest of the show. However, the gap between the events at the pilot and the events at episode 02 is one week away, too short to argue an office makeover.
Spoiler: Stacey and Greyson are the only regular characters whose relatives are never seen on screen (nor even in each character's big events). Their family members are just mentioned. Guardian angels do not count.