The average size worn by the women on the set was 0-2. Jane Krakowski, who wore a size 6, reportedly said that some days she felt like a "fat cow".
Lara Flynn Boyle audition to play Ally. Although she didn't win the role, David E. Kelleyliked her so much that he wrote the character of Helen Gamble on The Practice (1997) just for her.
Ling Woo wasn't originally intended to be a regular. David E. Kelley liked Lucy Liu so much as a guest star, he and the writer decided to reveal that she has a law degree and join the firm after a few episodes, giving her a reason to be there.
Peter MacNicol does not appear in the pilot, though he's in the second episode as a guest star. He joined the regular cast later in the first season.
Gil Bellows plays William ("Billy") Thomas. In The Shawshank Redemption (1994), he plays Thomas ("Tommy") Williams.
Creator David E. Kelley originally envisioned Bridget Fonda in the role of Ally McBeal.
Stephen Colbert auditioned for the role of Richard Fish.
Robert Downey Jr was fired from the show in Season 4 for being impossible to work with on set due to his drug problems at the time.
The song "Tell him" by various different artists, including the original by The Exciters, written by Bert Berns, is featured in 52 out of 112 episodes.
The show was cancelled in May 2002 because of falling ratings.
Nell's real name is Morgan.
In addition to Calista Flockhart , only Greg Germann and Jane Krakowski are credited in every episode.
John's frogs are named Millie and Stefan.
Ally McBeal (1997) takes place in the same world as David E. Kelley's other television series The Practice (1997). Guest star Dylan McDermott appeared in the crossover episodes Ally McBeal: The Inmates (1998) and Ally McBeal: These Are The Days (1998) as his character "Bobby Donnell". The Practice (1997) premiered six months before Ally McBeal (1997).
Liza's real name is Debbi.
David E. Kelley never considered doing a crossover episode, in which Ally McBeal meets Doogie Howser from David E. Kelley's earlier television series Doogie Howser, M.D. (1989).
The actors who play the most frequently recurring judges, Albert Hall and Dyan Cannonwere born in the same year, 1937.
In Scary Movie 2, Brenda Meeks comments, "Cindy! This is a skeleton, this is bones. Would you run from Calista Flockhart?" Regina Hall, who plays Brenda, recurred and was later a regular on the series when Scary Movie 2 was released. The comment refers to Calista Flockhart, who plays Ally.
There is a character in Mortal Kombat (1992) named Johnny Cage, the same name as the character played by Peter MacNicol in this series.
Spoilers
The trivia item below may give away important plot points.
At the start of season four, in an effort to boost ratings, Robert Downey, Jr. was hired to play Larry Paul, Ally's love interest. The ratings increased and David E. Kelley began planning to end that season with Ally and Larry's wedding. Before production on the season finale could begin, Downey was arrested on a drug-related charge. Despite Kelley's objections, Fox fired Downey, forcing Kelley to write a new season finale that removed Larry from the series, and re-write and re-shoot a new ending to the previous episode to remove all references to the aborted wedding storyline. Ironically, the episode's title remained "The Wedding".