The critically acclaimed BBC drama Blue Lights returns for a third season on September 29, 2025, on BBC iPlayer, plunging viewers back into the intense and morally complex world of policing in Belfast. The series follows a group of rookie and response officers for whom every call-out is a high-stakes test of judgement, courage, and survival. As the personal and professional lives of the characters become ever more intertwined with the city’s unique pressures, the exceptional ensemble cast continues to deliver powerhouse performances. Here is a complete guide to the talented actors who bring this gripping series to life.
Blue Lights Season 3 cast list
1. Sian Brooke as Grace Ellis
Sian Brooke, a graduate of the Royal Welsh College of Music & Drama, is a versatile and acclaimed actress with an extensive career on stage and screen. She is perhaps best known to international audiences for her pivotal role as Eurus Holmes, the secret sister of Sherlock, in the BBC’s Sherlock, a performance that showcased her ability to portray intense and unpredictable characters. Her television work also includes significant roles in The Catch and Stella, while on stage, she has been praised for her performances with the Royal Shakespeare Company and the National Theatre, earning an Olivier Award nomination.
In Blue Lights, Brooke serves as the emotional anchor of the series as Grace Ellis, a former social worker who joins the police force later in life. Her portrayal brings a unique depth and maturity to the rookie experience, as Grace’s past life informs her compassionate yet resolute approach to policing. Brooke masterfully conveys the constant internal conflict between her innate empathy and the harsh realities of the job, making Grace’s journey of adaptation and resilience one of the most compelling narratives on television.
2. Nathan Braniff as Tommy Foster
Nathan Braniff landed the role of Tommy Foster in Blue Lights as his first major professional acting credit, making his compelling performance all the more remarkable. He was cast straight out of drama school, demonstrating a raw talent that perfectly captured the essence of a young, idealistic recruit thrown into the deep end. His naturalistic and understated style brings an everyman quality to the series, allowing audiences to easily see themselves in his shoes as he navigates the shocking realities of frontline policing.
As Tommy, Braniff portrays a character who is often the moral compass of the group, yet is constantly tested by the cynicism and danger that surrounds him. His journey from a wide-eyed probationer to a more seasoned, though still vulnerable, officer is a central arc of the show. Braniff’s ability to express fear, determination, and doubt with subtlety makes Tommy’s survival and development a source of constant tension and investment for the audience.
3. Katherine Devlin as Annie Conlon
Katherine Devlin, an actress from Belfast, has built a solid career in film and television prior to her breakout role in Blue Lights. She appeared in the horror film The Dare and had a recurring role in the historical drama The Last Kingdom, demonstrating her range across genres. Her authentic presence and ability to portray gritty, determined characters made her a perfect fit for the world of Blue Lights, where she plays one of the three central rookies navigating the treacherous terrain of the Police Service of Northern Ireland.
As Annie Conlon, Devlin brings a fierce, street-smart energy to the show. Her character, a young woman from a working-class Belfast background, often has a more intuitive understanding of the community dynamics than her colleagues. Devlin excels at portraying Annie’s toughness and vulnerability in equal measure, as she must constantly prove herself while confronting loyalties and threats that hit close to home. Her performance adds a crucial layer of local authenticity and raw ambition to the series.
4. Martin McCann as Stevie Neil
Martin McCann, a native of Belfast, is one of Northern Ireland’s most prominent actors. He first gained significant attention for his lead role in the film The Mighty Celt and has since built an impressive international career. McCann starred in the lead role of Ciaran in the BBC series The Frankenstein Chronicles and delivered a powerful performance as a soldier in the film ’71. His intense screen presence and ability to convey deep internal conflict make him a formidable talent, perfectly suited for the complex world of Blue Lights.
In the series, McCann plays Stevie Neil, a seasoned and respected officer who acts as a mentor to the new recruits, particularly Grace Ellis. McCann brings a world-weary authority and a palpable sense of experience to the role, making Stevie a pillar of the station. However, he also skillfully reveals the character’s own demons and the psychological toll of a long career on the front lines. The dynamic between Stevie and the rookies provides some of the show’s most poignant and instructive moments.
5. Frankie McCafferty as Barney
Frankie McCafferty is a veteran Irish actor with a career spanning over four decades, encompassing theatre, film, and television. He is a familiar face in Irish productions, with memorable roles in films like The General and The Boxer, as well as numerous appearances on popular TV shows such as Ballykissangel and Single-Handed. His extensive experience allows him to bring a grounded, lived-in authenticity to every role he plays, often stealing scenes with his nuanced character work.
In Blue Lights, McCafferty plays Barney, a senior officer within the station. He serves as a vital link between the frontline officers and the upper echelons of the force, often dealing with the bureaucratic and political pressures that come with policing in Belfast. McCafferty imbues Barney with a mix of weary pragmatism and a deep, if sometimes hidden, concern for his officers. He represents the institutional memory of the service, a man who has seen it all but is still trying to do his job effectively.
6. Andi Osho as Sandra Cliff
Andi Osho is a multi-talented English performer who first gained fame as a stand-up comedian before successfully transitioning into a dramatic actress. She appeared in the BBC drama The Capture and the Netflix series The Last Bus, proving her ability to handle serious, high-stakes roles. Osho’s background in comedy gives her a sharp timing and intelligence that translates brilliantly into dramatic performances, allowing her to deliver dialogue with precision and power.
Osho joins the cast as Sandra Cliff, a high-ranking officer who brings a no-nonsense, strategic approach to the Belfast district. Her character is likely tasked with managing the fallout from the officers’ actions and the complex relationship between the police and the community. Osho’s commanding presence makes Sandra a formidable figure, someone who operates on a different level than the frontline recruits but whose decisions directly impact their safety and effectiveness on the streets.
7. Joanne Crawford as Helen McNally
Joanne Crawford is an accomplished actress from Northern Ireland, known for her powerful performances in theatre, film, and television. She has appeared in projects such as The Fall, starring Gillian Anderson, and the film Belfast, directed by Kenneth Branagh. Her ability to portray strong, often emotionally complex women with a quiet intensity has made her a respected figure within the industry and a perfect fit for the gritty realism of Blue Lights.
As Helen McNally, Crawford plays a character deeply embedded in the social fabric of the city. While her specific role is kept under wraps, her casting suggests a significant part, potentially as a family member of an officer, a community leader, or a figure from the criminal underworld. Whatever her character’s allegiance, Crawford’s proven talent ensures a performance filled with depth and authenticity, adding another layer to the show’s rich exploration of Belfast life.
8. Charlie Maher as Fogerty
Charlie Maher is a rising talent in the Northern Irish acting scene. As Fogerty, one of the other probationary officers, Maher represents the wider group of rookies learning the ropes alongside Tommy, Annie, and Grace. His character provides a crucial perspective on the shared experiences and camaraderie within the training class, highlighting the different ways young cops cope with the immense pressure.
9. Dearbháile McKinney as Aisling
Dearbháile McKinney brings her talent to the role of Aisling, a character who exists within the community the police are trying to serve and protect. Her role likely explores the civilian perspective, showing how the work of the Blue Lights directly impacts the lives of ordinary people in Belfast. McKinney’s performance helps to ground the series in the human stories beyond the police badges.
10. Frank Blake as Shane Bradley
Frank Blake, known for his role in the Viking drama The Last Kingdom, joins the cast as Shane Bradley. His character’s name suggests a potential love interest, family connection, or a figure from a suspect’s world. Blake’s rugged intensity makes him well-suited for the tense environment of the show, and his presence is sure to create new dynamics and conflicts for the main characters.
11. Matthew Forsythe as Aodhan McAllister
Matthew Forsythe is another skilled actor from Northern Ireland. As Aodhan McAllister, he plays a character who could be a fellow officer, a criminal antagonist, or a civilian caught in the crossfire. The name and Forsythe’s casting point to a character deeply connected to the local landscape, whose actions will inevitably intertwine with the lives and duties of the response team.
