10 Criminal Minds Guest Stars Who Stole the Spotlight From the Main Cast

Criminal Minds is a procedural television staple. The original series ran for 15 seasons from 2005 to 2020 before being revived as Criminal Minds: Evolution in 2022. The popularity of Criminal Minds’ original run led to some high-profile actors and actresses appearing in the serial-killer drama series.

Due to the series’ dark nature and procedural aspect, the guest stars on Criminal Minds tended to play UNSUBs. If not an UNSUB, then the big-name stars often played somebody from a main character’s personal life. These unique roles allowed brilliant stars to shine brightly in roles that may be unorthodox for their filmography.

Aubrey Plaza is Undeniably Entertaining as Cat Adams

Aubrey Plaza may be known for her comedic performances on television, but that doesn’t mean she’s incapable of bringing her dramatic A-game. Aubrey Plaza guest-starred on Criminal Minds as Cat Adams, a hitwoman with the moniker of «Miss.45.» Adams and her cadre of hitmen and women were targeting FBI technical analyst Penelope Garcia, so the BAU set up a sting to take them down. However, Cat Adams proved to be much more calculating than meets the eye.

Cat Adams and SSA Dr. Spencer Reid would face off in this sting and numerous more times during other recurring guest appearances. Plaza played her in such a way that Adams can get under one’s skin and bring out the darker parts of them. Cat Adams also has a funny aspect to her character that creates a compelling contrast with her obvious psychopathic nature. The popularity of Cat Adams made Aubrey Plaza an easy fan favorite guest star, and fans fervently looked forward to her appearances.

Mark Hamill was the Perfect Actor to Play The Replicator

Mark Hamill became a household name for his role as Luke Skywalker in the Star Wars film series. He strays far from his iconic hero role to play one of the most brilliant serial killers the BAU has ever faced. Season 8 saw the BAU team facing a unique adversary in the form of a copycat serial killer known as «The Replicator.» What set The Replicator apart was that he was specifically replicating cases the BAU team had worked on, and was targeting members of the team in an elaborate revenge plot.

While most of The Replicator’s antics occurred without seeing the man himself, Mark Hamill made his screentime count in the explosive Season 8 finale named after his character’s moniker. Hamill easily exuded the righteous vengeance that powered the UNSUB, delivering his lines with powerful derision towards the BAU team. One of the most terrifying aspects of The Replicator was his intellect and his ability to outsmart the BAU, and Hamill didn’t miss a beat matching the offscreen actions of his character onscreen. Mark Hamill was the perfect actor to bring The Replicator to life, and he made the Season 8 finale a showstopping event.

Jason Alexander Wholly Transforms to Become Professor Rothschild

Jason Alexander is almost unrecognizable in his role on Criminal Minds. Alexander elevated the Season 4 episode «Masterpiece» to new heights and made it a standout episode for the season. Jason Alexander played the psychopathic killer who uses the pseudonym of Professor Rothchild, who approaches SSA Dr. Spencer Reid and SSA David Rossi outside a seminar and turns himself in. Rothchild tells them he is a serial killer with hostages, and challenges them to save the hostages before they die.

Jason Alexander, as Professor Rothchild, is one of the best one-off UNSUB performances in Criminal Minds. Alexander truly transformed into a wholly different person to play the enigmatic genius Professor Rothchild. Rothschild gets under Rossi’s skin from the moment they meet, setting them up on a collision course for the episode. Rossi’s mental duel with Rothschild in interrogation makes for fantastic TV, and it’s a true credit to Jason Alexander that he matched Joe Mantegna’s fantastic performance as SSA David Rossi.

C. Thomas Howell is Terrifying as George Foyet

C. Thomas Howell is one of the most popular actors of his era. He has acted in a wide variety of roles, and he put that experience to use during his time on Criminal Minds. C. Thomas Howell took on the role of George Foyet, a serial killer known as «The Reaper.» «The Reaper» is one of the worst serial killers the BAU has ever come across. He would forever change the lives of the BAU team, especially that of SSA Aaron Hotchner.

C. Thomas Howell’s George Foyet truly embodies the worst of humanity. He is a true psychopath who, at times, seems more like a monster than a man. Howell delivers a terrifying performance, to the point where he can make viewers shudder through a TV screen. His obsessive and relentless pursuit of Aaron Hotchner and his family is one of the most compelling arcs of Criminal Minds. The way C. Thomas Howell balanced pure darkness with the high-functioning mind of a true predator allowed him to create an iconic villain for the series.

Jane Lynch Brought Heart to the Role of Diana Reid

Jane Lynch is best known for her comedic role in the musical comedy series Glee. However, she has a dynamic range and puts that to work in Criminal Minds. Jane Lynch was tapped to play the most important person in SSA, Dr. Spencer Reid’s life, and his mother, Diana.

The role of Diana Reid is not an easy one. Diana was a college literature professor before being diagnosed with paranoid schizophrenia, which caused the breakup of her marriage with Spencer’s father. From a young age, Reid had to support his mentally ill mother until he was forced to institutionalize her when he was 18. Diana’s character is frenetic but has that same erudite core that she shares with her son. Lynch does a phenomenal job playing this recurring guest star as she struggles with an awful illness, but still manages to be a port in the storm for her son.

Forest Whitaker was Fantastic as SSA Sam Cooper

Forest Whitaker is an incredibly accomplished actor who has a diverse filmography. Whitaker packs an emotional punch with every role he takes on, and his role in Criminal Minds is no exception. He was asked to take on a unique role for Criminal Minds and play SSA Sam Cooper, leader of a unique profiling team from within the BAU that reports directly to the Director of the FBI in the interest of speed.

Forest Whitaker established right out of the gate that Sam Cooper is an unorthodox character. He abhors bureaucracy and uses an old MMA gym as his team’s base of operations. His quirks don’t feel forced, and rather make complete sense for the character Whitaker is embodying. Sam has an intense aura that makes his character feel more like a powerful warrior than an FBI agent. Forest Whitaker’s stellar performance would get Sam and his team more time in the spotlight as they became the central focus of the first and only season of Criminal Minds: Suspect Behavior, the first ill-fated spinoff of the series.

Ben Savage Showed Fans a New, Younger Version of SSA Jason Gideon

Ben Savage is a TV veteran with decades of experience under his belt. He had a monumental task when he appeared on Criminal Minds as a younger version of Jason Gideon. Savage’s younger version of Gideon appears in flashbacks with a younger version of fellow BAU founder SSA David Rossi as they investigate Gideon’s murder by a killer from their past.

The character of SSA Jason Gideon is remembered fondly by longtime viewers of the series. Savage portrayed a version of this character that was essentially an early draft of the character fans were introduced to in Season 1 of Criminal Minds. Ben Savage used his skills to provide a look into a version of this character who wasn’t haunted by all the horrors that he had seen after decades in the BAU. Savage’s portrayal opened a new window into a classic character and allowed Jason Gideon to come to life once again.

Tim Curry Gave a Masterful Performance as Billy Flynn

Tim Curry is one of the best actors of his generation. He’s known for a slew of phenomenal film performances, and in Season 6 of Criminal Minds, he proves his dominance as an actor is not limited to the big screen. Tim Curry plays Billy Flynn, a prolific serial killer and rapist with potentially one of the highest body counts in the series.

Tim Curry appears in a thrilling two-part episode duology of Criminal Minds that serves as the finale of Season 5 and the premiere of Season 6. His killer is nicknamed «The Prince of Darkness» due to the unique signature of killing during blackouts. He also leaves behind a survivor who witnessed the traumatic moment. Curry’s character of Billy Flynn is undoubtedly monstrous, but is incredibly compelling, and his unsettling humor adds bizarre layers to his dark character.

Matthew Lillard is Chilling as David Roy Turner

Matthew Lillard is an actor with an extensive filmography ranging from horror to comedy. He’s most well-known for portraying one of the original Ghostface killers in the horror movie Scream, which would become a cult classic and spawn an iconic film series. He taps into a similar darkness to play a twisted rapist and serial killer in Criminal Minds Season 8 with dark intentions.

Matthew Lillard plays David Roy Turner, a convicted rapist who forms a serial-killing partnership with a budding psychopath teenage boy, Toby Whitewood. The bond of these two killers is unlike any that has been shown on the show before. Instead of a dominant/submissive partnership or equal partnership, Lillard’s Turner teaches Whitewood how to be a serial killer. Lillard’s performance has fans’ skin crawling as he plays this predatory killer. Lillard elevates the dynamic between these two killers by imbuing all of their interactions with twisted undertones that keep viewers on edge and locked into the episode.

Sheryl Lee Ralph Delivered a Stellar Performance as Hayden Montgomery

Sheryl Lee Ralph is a phenomenal and criminally underrated actress who is finally getting the accolades she deserves. Before she achieved mainstream fame on the popular sitcom Abbott Elementary, she guest-starred in Criminal Minds. Sheryl Lee Ralph played Hayden Montgomery, a diplomat and the second ex-wife of series lead SSA David Rossi.

Hayden and Rossi have an incredibly loaded relationship, and their first interaction on screen is incredibly heavy. Rossi had recently learned that Hayden had given birth to his child and concealed the pregnancy from him. Rossi learned that his daughter existed decades later when she tracked him down and told him the truth. Rossi and Hayden had a lot of emotions to unload, and Sheryl Lee Ralph was the perfect person to select for such a role. Sheryl Lee Ralph nails Hayden’s strong nature and the complex emotional niches that come with someone who had to make the decision she did.