Julian Kostov (born 25 August 1989) is a Bulgarian actor and filmmaker. In 2025, he starred as Marek in the West End production of Till the Stars Come Down at the Theatre Royal Haymarket, a transfer from the Royal National Theatre. He has been described as the first Bulgarian actor to perform in a West End production.
In 2026, he was nominated for a Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series as part of the cast of the HBO series The White Lotus.
He gained international recognition for his roles in Shadow and Bone (2021) and as the antagonist Vladimir Makarov in Call of Duty: Modern Warfare III (2023).
His film career includes starring roles in the action-comedy Fight or Flight (2025) alongside Josh Hartnett, the anti-superhero comedy The Toxic Avenger (2023), and the war dramas The Last Front (2024) and Another Mother's Son (2017). He is slated to appear in the upcoming Netflix feature The Boy in the Iron Box, produced by Guillermo del Toro.
Beyond his acting career, Kostov is the founder of JupiterLights Media and co-founder of Five Oceans alongside Academy Award-nominee Maria Bakalova, with multiple award-winning projects as a producer and director, including Triumph, Bulgaria's official submission for the 97th Academy Awards.
Kostov has spoken about the need for greater representation of Slavic and Balkan actors and the normalization of foreign accents on screen.
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Early life and education
Julian Kostov was born on 25 August 1989 in Varna, Bulgaria. At the age of 12, Kostov became a pentathlon champion for his age group. He was a 10-time National Swimming Champion from 2005 to 2009. In 2008, he earned the Master of Sport title in Swimming. Kostov holds over 60 medals as a professional swimmer, including a bronze medal at the 2007 Balkan Games. He attended the Spanish-language Frederic Joliot-Curie School in Varna, before entering post-secondary studies at Tilburg University, where he majored in international business.
After two years in the Netherlands, Kostov decided to move to the United Kingdom and pursue a career in acting, inspired by Heath Ledger's performance in The Dark Knight. He transferred to Cardiff Metropolitan University to finish his studies, graduating with a bachelor's degree in Business Studies in 2011. He was admitted to the National Youth Theatre that same year. Kostov began auditioning for agents, eventually signing with one. He later switched to a different agent and landed a Gillette commercial. During that period, he also took classes at Anthony Meindl's Actor Workshop in London.
Career
Early career and critical breakthrough (2014–2020)
Kostov began his acting career with a guest role on 24: Live Another Day in 2014, followed by appearances in Ben-Hur and London Has Fallen. In 2017, Kostov portrayed the historic figure Feodor "Bill" Burriy in the World War II drama Another Mother's Son, receiving positive reviews for his performance. Critics highlighted his "brooding, internalised quality," with HeyUGuys observing that he bore an "uncanny resemblance to a young Robert De Niro" in the film.
That same year, he appeared in the horror film Leatherface, playing Ted Hardesty, the father of the original franchise's protagonists. Between 2018 and 2020, he held recurring television roles in A Discovery of Witches, Berlin Station, and Treadstone.
Breakthrough and international recognition (2021–present)
In 2021, Kostov gained international recognition as Fedyor Kaminsky in the Netflix series Shadow and Bone In 2023, he portrayed the antagonist Vladimir Makarov in Call of Duty: Modern Warfare III.
In 2024, Kostov provided the voice for Aleksei in James Gunn's DC Universe reboot series Creature Commandos. The same year, he produced and starred in Triumph, which premiered in the Platform competition at the Toronto International Film Festival and was selected as the Bulgarian entry for the Academy Award for Best International Feature Film at the 97th Academy Awards.
In 2025, Kostov appeared in several major productions. He starred as Aleksei in the third season of the HBO series The White Lotus, earning a Screen Actors Guild Award nomination in 2026. Kostov appeared as Budd Berserk opposite Elijah Wood and Peter Dinklage in the superhero splatter film The Toxic Avenger, which received a wide release in 2025.
In the same year, Kostov also starred alongside Josh Hartnett and veteran co-star Katee Sackhoff in the action-comedy Fight or Flight. His portrayal of the caustic operative Aaron Hunter was highlighted as a comedic standout, with Screen Rant observing that both actors "chew the scenery with aplomb."
Kostov is slated to appear in the upcoming Netflix feature The Boy in the Iron Box, produced by Academy Award-winner Guillermo del Toro.
Stage and West End debut
In 2025, he became the first Bulgarian actor to perform in a West End production, starring as Marek in the National Theatre's transfer of Till the Stars Come Down at the Theatre Royal Haymarket.
His portrayal of the Polish groom Marek received widespread critical acclaim from major UK publications. Clive Davis of The Times noted that his presence elicited visceral "gasps from the audience" during the play's climax. The Stage praised his "energizing" performance, describing the character as "by turns charming, impulsive, and prickly," while Time Out London called him a "bright light" who played the role with "gusto."
The Evening Standard noted that Kostov "impressed," bringing "range and passion, as well as an excellent comic touch" to the role. The Sunday Express further described his performance as a "stand out delight," and theatre publication All That Dazzles called him "charming and charismatic," adding it was a performance "impossible not to fall in love with."
Other endeavours
In 2014, Kostov founded JupiterLights Media (formerly JupiterLights Productions), a UK-based production company. The company produced the horror-thriller film The Dare (2019). JupiterLights is also credited with managing the early international career of Academy Award-nominee Maria Bakalova.
Alongside Bakalova, Kostov co-founded the production company Five Oceans, which focuses on bringing Balkan and Eastern European stories to a global audience. Through Five Oceans, he co-produced the satirical drama Triumph (2024), in which he also starred.
Acting credits
Filmmaking credits
Early Birds (2015) – writer, producer
The Dare (2019) – producer, second unit director
What Stays After (2024) – producer
You Don't Exist (2024) – producer
Triumph (2025) – producer, actor
The Day She Will Be Born (2025) – producer, actor
Shattered Bonds (2025) – executive producer, actor
Red Market (2024) – director, writer
Music
Kostov has also released music as a recording artist, with singles including "Rain", "Home (My Gaia)", "Groundhog Day", and "420".