Pretty Little Liars is about a group of friends - Spencer Hastings, Hanna Marin, Emily Fields and Aria Montgomery. After their leader, Alison DiLaurentis, goes missing, they all start receiving anonymous messages. This brings them together, closer than ever, and begins one of the most mysterious and most thrilling television shows of all time. Fans were on this journey with the main characters, trying to figure out who was sending the messages, why, where Ali was and more.

Throughout the series, some guest stars helped make this story even more exciting, and down below, we are ranking some of the most memorable ones.

12. I. Marlene King

Marlene King is a writer, producer and director. More specifically, she is the executive producer and showrunner of Pretty Little Liars! She also wrote Now and Then (a film that is about a different group of girlfriends) and adapted another one of Sara Shepard’s novel series, The Perfectionists, into another television series for Freeform. In 2017, she appeared as a photographer in a PLL episode called “Til DeAth Do Us PArt”. She obviously did tons of work behind the camera, but it was probably fun to be seen on the show, too. Look for her next time this series is rewatched!

11. Emerson And Atticus King

Marlene King’s sons, Emerson and Atticus, also sometimes appeared as extras in this teen drama! Emerson, for instance, played one of Alison’s students in the series finale. And Atticus was one of the children who ran away when Toby was encountered on the street (in “Know Your Frenemies), and he was the kid Hanna babysat (in “The First Secret).

With a mother like theirs, these two may go onto work in show business, too. Wherever they end up, it is neat to think that they took part in this popular TV show like this, right alongside their talented mom!

10. Adam Lambert

One of the biggest guest stars from Pretty Little Liars is Adam Lambert. He played himself on an episode in 2012, which as titled “This Is a Dark Ride”. Here, the girls went aboard the Rosewood Ghost Train for some Halloween fun, and even though things went real south real fast, Adam Lambert was still there, performing “Trespassing” and “Cuckoo”. For those who don’t know, this singer rose to fame through American Idol in 2009, and since then, he has sold over 3 million albums and 5 million singles worldwide, so having him on this show was awesome!

9. Robbie Amell

Noel Kahn played an integral role in this story, and one times, fans got to meet his older brother, Eric. Who played this character, in “The Kahn Game” from 2012? Well, it was Robbie Amell! Robbie Amell is a Canadian actor who has been seen on other television shows, such as The Tomorrow People, The Flash, Life with Derek, True Jackson and Revenge, and in films like Scooby-Doo! The Mystery Begins, Scooby-Doo! Curse of the Lake Monster, The Hunters and The DUFF. Even though he was not on PLL for very long, many people probably recognized him from another one of these popular works.

8. Missy Franklin

Missy Franklin is another big name, and she, too, appeared as herself. In 2013, there was an episode called “Will the Circle Be Unbroken?”, and in this, Emily got to meet this star. See, Emily is a swimmer in this show, so it makes sense that a connection with a five-time Olympic gold medalist would be highlighted.

Currently, Missy Franklin holds the world record in the 200-meter backstroke and in the 4×100-meter medley relay, which is super impressive! With all the excitement found through PLL, some may not even remember this guest star, but she is another one who needed to be mentioned on this list.

7. Rumer Willis

Rumer Willis is up next, and she portrayed Zoe in “The Guilty Girl’s Handbook” in 2013. Zoe was an organizer for Habitat for Humanity, and she invited Emily to come with her to Nicaragua to do some work. Rumer Willis is Bruce Willis’ and Demi Moore’s oldest daughter (They also have Tallulah and Scout). Besides being on Pretty Little Liars, she also won season 20 of Dancing with the Stars and made her Broadway debut in Chicago as Roxie Hart.

Yes, Rumer Willis’ family is quite famous, so having her on this television show was pretty exciting.

6. Patrick J. Adams

Patrick J. Adams portrayed Hardy in 2010, and the name of the episode was called “Reality Bites Me”. Why is this significant? Well, first of all, Patrick J. Adams is best known for playing Mike Ross, the brilliant college dropout turned unlicensed lawyer, in Suits. But it gets better: In December 2016, he married Pretty Little Liars’ star Troian Bellisario, who is known by many as Spencer! This couple met in 2009, while working on the play Equivocation, and on October 8, 2018, he announced that he and Troian had a daughter together!

5. Sara Shepard

Here is a super fun guest star… Sara Shepard wrote the bestselling Pretty Little Liars and The Lying Game book series, both of which have been turned into television shows on Freeform. She also wrote The Perfectionists book series, which is about to premiere on Freeform, starring Sasha Pieterse and Janel Parrish as Alison DiLaurentis and Mona Vanderwaal. On PLL, this author was seen on camera in two different episodes; in 2015’s “I’m a Good Girl, I Am”, she played a news reporter, and in 2010’s “The Homecoming Hangover”, she played Miss Shepard, a substitute English teacher for Aria’s class.

4. Rose Abdoo

Rose Abdoo is another notable name who appeared in two episodes of Pretty Little Liars. First, there was “Bite Your Tongue” in 2014, and she played Dr. Sandy; Dr. Sandy is Dr. Ackard’s assistant, Dr. Ackard, who also works in this dental office, is the mother of Sean, Hanna’s ex-boyfriend.

Then, there was “There’s No Place Like Homecoming” in 2010, and she played a fortune teller at the homecoming dance. Here is a fun fact for everyone: Rose Abdoo is known for playing local mechanic, Gypsy, in Gilmore Girls, which was filmed on the same set as Pretty Little Liars!

3. Claire Holt

For five episodes in 2011, Claire Holt portrayed Samara Cook. Claire Holt is an Australian actress who also played Rebekah Mikaelson on The Vampire Diaries and its spinoff series The Originals, Emma in H2O: Just Add Water and Kate in 47 Meters Down. Her PLL character, Samara Cook, dated Emily in season 2. Their relationship started when Emily was trying to help Paige with coming out, since Samara worked for an LGBTQ+ pride group, and - go figure - the relationship ended due to an interference by A. Claire Holt is another familiar face that was neat to see on this beloved show!

2. Lulu Brud

Lulu Brud is an actress and interior designer, and for nine episodes, she portrayed Sabrina in Pretty Little Liars. To recap, Sabrina worked at The Brew. She gave Spencer some goodies, to help calm her nerves, which resulted in Toby eating some unique gummy bears. She refused to give Aria the key to Ezra’s apartment, which resulted in Aria and Emily stealing the key and which put a damper on Sabrina’s and Emily’s romantic relationship. And off the show, Lulu Brud is best friends with Troian Bellisario, meaning this is another important real-life connection that fans got to see via this series!

1. Ryan Merriman

Last but not least, we have Ian Thomas, who, for 16 episodes, was Ian Thomas on PLL. Ryan Merriman started acting when he was just 10, and since then, people may have seen him in The Ring Two, Final Destination 3 or Disney Channel original movies like A Ring of Endless Light, The Luck of the Irish and Smart House.

Today, though, the people who are reading this piece may know him best as Ian Thomas, who was married to Melissa Hastings until he passed away, who coached the Rosewood High field hockey team and who was a part of the N.A.T. Club when he was a student.