*Charisma Carpenter, who plays Cordelia, auditioned for the role of Buffy.
*Both James Marstars (Spike) and Nathan Fillon (Caleb) auditioned for the role of Angel.
*Julie Benz, who plays Darla, auditioned for the role of Buffy.
*Elizabeth Anne Allen, who plays Amy, auditioned for the role of Buffy.
*Katie Holmes and Selma Blair were considered for the role of Buffy.
*Bianca Lawson, who plays Kendra, auditioned for the role of Cordelia.
*The characters of Spike, Oz, Faith and Wesley were all supposed to be killed off, but all ended up living on. Also, the characters of Joyce and Jenny were supposed to die sooner.
*Danny Strong, who plays Jonathan, auditioned for the role of Xander.
*Joss Whedon is known to plan his storylines years in advance. Clues to Dawn's arrival can be found as early as the third season although she doesn't show up until the fifth.
*Buffy's birthday occurs in the episode first aired on or near January 19th.
*Joss Whedon supplies the voice of the Mutant Enemy mascot which says "Errg...Arrgh" heard at the end of almost every episode.
*Nicholas Brendan is older than most the cast including David Boreanaz. He was 25 years old when he was first cast as 16 year old Xander Harris.
*"Mutant Enemy", Joss Whedon's production company, was the name he gave his first typewriter when he was 15. The logo was created in 20 minutes when he was told he had to have one.
*The episode "Earshot" in season three was about a student supposivly planning a mass murder on campus. It was schedualed to air a week after the Columbine shooting but was delayed until the next season.
*The season three finale ("Graduation Day") was delayed for three months after the abundant happenings of school violence.
*The death of Larry in the season three finale "Graduation Day" was not confirmed until season six.
*Sarah Michelle Gellar and Alyson Hannigan are the only actors to appear in every episode. Nicholas Brendon missed only one episode in the early 7th season.
*The first and last seasons of the show were the only seasons not to have a Buffy birthday episode. This is to honor the "back to the beginning" theme of the last season.
*In the series finale "Chosen", there is a scene with Buffy, Willow and Xander talking about "teen" stuff. Giles mutters to himself "the earth is definetly doomed" as they walk away. This is a referance to the end of the Buffy pilot episode Welcome to the Hellmouth/The Harvest, although here Giles adds the word "definately." This is to honor the "back to the beginning" theme of the last season.
*In the series finale, Giles says there is a hellmouth in Cleveland. This is a referance to the season three episode "The Wish" in which, in an alternate reality where Buffy never comes to Sunnydale, Giles phones her watcher and says "yes, I know there is a lot of demonic activity in Cleveland... there happens to be a hellmouth in Sunnydale..."
*There is a half hour long pilot directed and finaced by Joss Whedon out of his own pocket to sell the show to the networks. It is similar to the "Welcome to the Hellmouth" although Angel, Jesse and the Master don't appear. Riff Regan played Willow and Stephan Toboolwsky played pricipal Flutie. They were replaced by Alyson Hannigan and Ken Lerner in the actual show. The library that appears is not the set from the show but the actual library of the Torrance High School where much of the Sunnydale High material was filmed.
*In "Conversations With Dead People", Amber Benson (Tara) was supposed to return as The First Evil impersonating Tara, but she didn't want to come back just as a villain. Cassie Newton from a recent episode played the part instead.