- Was originally pitched as a feature with Lindsay Lohan as Blair Waldorf. When that fell through, its backers (who had the rights to the stories) approached Josh Schwartz about turning it into a series.
- Originally, Georgina Sparks was offered to Mischa Barton, who turned down the role. Michelle Trachtenberg was then cast as Georgina Sparks.
- Every episode title is a word play on the title of a movie.
- The Gossip Girl TV series is based off of the Best Selling Novels "Gossip Girl" written by 'Cecily Von Ziegesar'.
- The name of Rufus' band, "Lincoln Hawk", is also the name of Sylvester Stallone's character in the movie Over the Top. That movie is mentioned several times as being a cult-classic in The O.C., the previous show from Josh Schwartz, the creator of this series.
- Leighton Meester had to dye her naturally blonde hair brunette merely to audition for the role of Blair Waldorf.
- The show's beginning date took place, chronologically, after it was aired. The show aired in Canada on September 18, 2007 and aired in the US on September 19, 2007. The show starts on Wednesday September 23, 2007 and ends on Saturday September 26, 2007, thus all dates in the Pilot fall after their air date.
- Blair Waldorf and Serena van der Woodsen live at 1136 Fifth Avenue, New York NY 10128 in the penthouse. Lily van der Woodsen and her family lived in suites at 455 Madison Avenue, New York, NY 10022 - otherwise known as the Palace Hotel until moving to the Milan Condominium at 300 East 55th Street, New York, NY.
- The character of Lily van der Woodsen was originally named Darla, until the writers changed it at the last moment.
- The series has become so popular that a tour of Gossip Girl sites has been created in New York City, by the same people who created the Sex and the City Tour.
- In the show, the character Chuck gets a dog and names him monkey. In the books, his character actually has a pet monkey
- Blake Lively, Leighton Meester and Penn Badgley are the only cast members to appear in every episode (Kristen Bell is heard in every episode, but does not actually appear onscreen until the finale).
- Penn Badgley was on the verge of quitting acting when he was offered the role of Dan Humphrey. He originally turned down the role but was persuaded to join the cast by producer Stephanie Savage.
- The CW did not want Ed Westwick to play Chuck Bass, insisting that "he looked more like a serial killer than a romantic lead".
- William Baldwin, who played Serena van der Woodsen's absentee father, avoided meeting his onscreen daughter Blake Lively until the cameras rolled so that they could have a more realistic, strained relationship.
- Leighton Meester and Sebastian Stan were briefly engaged during the course of the series.
- Blake Lively and Penn Badgley who played onscreen couple Serena and Dan dated from 2007 to 2010.
- Matthew Settle and Kelly Rutherford who played husband and wife dated in real life.
- A spin-off set in the 80s and focusing on the characters of Lily and Susan Rhodes was planned. The CW passed on the pilot which was eventually aired as part of the show's second season.
- Headmistress Queller was named after writer/producer Jessica Queller.
- SPOILER: Penn Badgley was not informed that he was Gossip Girl until the night before the scene revealing this detail was shot.
- {Pilot (#1.1)}
- Was originally pitched as a feature with Lindsay Lohan as Blair Waldorf. When that fell through, its backers (who had the rights to the stories) approached Josh Schwartz about turning it into a series.
- This is the only episode so far in the series that Chuck Bass and Nate Archibald ride a public bus to school, unlike the usual private limo ride.
- Unlike the first book, which starts out with Blair talking to Isabel and Kati, the episode starts with Serena on the train back home.
- The Constance Billard School for Girls is based on The Nightingale-Bamford School on the Upper East Side of Manhattan. Cecily von Ziegesar, the author of the books which the series is based on, attended this prestigious school.
- In the pilot Eleanor Waldorf (Blair's mother) is played by actress Florencia Lozano instead of Margaret Colin.
- Chuck facetiously remarks that he admires Serena for sleeping with her 'best-friend's boyfriend'. Chuck would later have sex with his best-friend's (Nate) (barely ex-)girlfriend (Blair) in the episode "Gossip Girl" (2007) {Victor/Victrola (#1.7)}.
- The dress Jenny wore to the Ivy League party is the same dress Blair gave her in "Gossip Girl" (2007) {The Wild Brunch (#1.2)}.
- Margaret Colin now takes over from Florencia Lozano as Eleanor Waldorf.

