Katey Sagal Joins Best Medicine Season 2 Cast as Louisa's Mother Kathleen
Television veteran Katey Sagal is heading to Port Wenn in Season 2 of Best Medicine, taking on the recurring role of Louisa's scheming and estranged mother.
Published 2 November 2026
Casting Announcement for Season 2
The television series Best Medicine is expanding its cast significantly for its second season by introducing a pivotal family member. Industry veteran Katey Sagal has officially been cast in a recurring capacity to portray the mother of Louisa. Her character, Kathleen Gavin, is set to make her dramatic entrance in episodes scheduled to air later in the current season.
This new addition promises to shake up the dynamics in the fictional setting. Viewers can expect plenty of tension when Kathleen finally appears on screen, bringing her unique brand of trouble to the small Maine community.
Meet Kathleen Gavin
According to the official character description released for the show, Louisa's mother is far from a warm and comforting parental figure. Kathleen is characterized as combative, deeply conniving, and relentlessly self-serving. In fact, official details note that she holds the dubious distinction of being the sole individual on earth who is entirely unwelcome in Port Wenn.
This personality stands in stark contrast to the sweet, selfless, and kind nature of her daughter Louisa, portrayed on screen by Abigail Spencer. The apple clearly fell far from the tree and rolled even further away, setting the stage for major family friction.
A Disliked Return to Port Wenn
Kathleen's arrival in the tiny Maine town follows a very long absence, and her comeback immediately disrupts the peace. Because of her past behavior and manipulative tendencies, the local townspeople have bestowed upon her the less-than-flattering nickname 'Shady Katie.'
Her unexpected reappearance is guaranteed to complicate Louisa's life immensely, dragging old baggage back to the surface and testing the patience of the entire local community.
Katey Sagal's Illustrious Television Career
The actress stepping into the role of Shady Katie boasts an extensive and iconic television resume spanning multiple decades. Katey Sagal spent all 11 seasons playing Peggy Bundy on the Fox comedy Married... With Children, cementing her status as a household name.
Later, she transitioned to intense dramatic work, portraying Gemma on FX's Sons of Anarchy throughout its seven-season run. That powerhouse performance earned her a Golden Globe Award in 2011 for Best Performance by an Actress in a Television Series — Drama.
Extensive Credits Across Genres
Beyond her signature roles, Sagal has lent her talent to numerous other celebrated television projects. Her expansive list of credits features appearances in The Conners, The Abandons, Rebel, Superior Donuts, 8 Simple Rules, Tucker, Boston Legal, Lost, This Is Us, and Shameless.
In addition to her live-action roles, she is a recognizable voice actress, bringing animated characters to life in long-running series such as Futurama and One Piece.
A Star-Studded Season 2 Guest Cast
Sagal joins a growing roster of notable guest stars appearing in Best Medicine Season 2. Martin Clunes is set to return as Dr. Robert Best, the father of Dr. Martin Best, who is played by Josh Charles.
Furthermore, the second season has welcomed other fresh faces, including Jack Cutmore-Scott as Parker, a professional monitor ensuring Martin complies with state medical board rules, and Andrea Martin as Judith, a feisty friend of Aunt Sarah.
News Overview
Katey Sagal has joined the cast of Best Medicine for Season 2 to play Louisa's estranged and conniving mother, Kathleen Gavin. Known locally as Shady Katie, the character's long-awaited return to Port Wenn will cause major complications for Louisa.
Key facts
- Katey Sagal will recur as Louisa's mother, Kathleen Gavin, in Best Medicine Season 2.
- Kathleen is described as combative, conniving, and unwelcome in Port Wenn.
- Townsfolk refer to Kathleen Gavin as Shady Katie.
- Louisa is played by Abigail Spencer.
- Katey Sagal won the 2011 Golden Globe for Best Performance by an Actress in a Television Series — Drama for Sons of Anarchy.
- Martin Clunes returns as Dr. Robert Best, father to Dr. Martin Best (Josh Charles).
- Jack Cutmore-Scott plays Parker, and Andrea Martin plays Judith in Season 2.