Death certificate confirms pulmonary embolism after months of cancer treatment

The cause of death of beloved actress Catherine O’Hara has been formally confirmed, bringing painful clarity to a loss that has shaken the film and television world.

Official records in the United States show that O’Hara died from a pulmonary embolism, a blood clot that travelled to her lungs. She passed away on 30 January at a hospital in Los Angeles. She was 71.

The death certificate also lists rectal cancer as an underlying, long term condition. It states that she had been receiving treatment since March 2025. While the blood clot was the immediate cause, the illness had been part of her life for nearly a year.

Pulmonary embolisms are sudden and often deadly. According to NHS guidance, they occur when a blood vessel in the lungs becomes blocked, usually by a clot that has travelled from elsewhere in the body. Symptoms can include breathlessness, chest pain and coughing up blood. In severe cases, they can be fatal without warning.

News of O’Hara’s cause of death has prompted a renewed wave of grief from colleagues, friends and fans. Tributes have continued to pour in for an actress celebrated not only for her extraordinary comic timing but also for her warmth and generosity behind the scenes.

Seth Rogen, who worked closely with her on the Emmy winning comedy The Studio, said he was devastated by her passing. He described her as hysterical, kind, intuitive and endlessly generous, adding that the world was lucky to have shared space with her talent.

Pedro Pascal, who appeared alongside O’Hara in The Last of Us, shared a deeply personal message online. He wrote that there was now less light in his world, but expressed gratitude for having known her and worked beside her.

O’Hara’s career spanned decades and genres. She became a household name through a blend of sharp comedy and emotional depth, earning particular acclaim for her role as Moira Rose in Schitt’s Creek. Her performance in the series earned her an Emmy award and cemented her status as one of television’s most distinctive performers.

Eugene Levy, who worked with O’Hara for more than fifty years, said words were inadequate to describe the loss. He spoke of the honour of knowing and collaborating with her across generations of work. Dan Levy, who played her son in Schitt’s Creek, described her as family long before she portrayed one on screen and said he would cherish every memory they shared.

Her impact reached far beyond television. For many audiences, O’Hara will always be remembered as the fiercely loving mother in the Home Alone films. Macaulay Culkin, who played her on screen son, wrote a heartbreaking tribute, expressing regret that he did not have more time and saying simply that he loved her.

Despite her immense success, O’Hara was known for her humility and discretion. She kept her illness private, continuing to work while undergoing treatment. Only after her death did the full extent of her health struggles become public.

She is survived by her husband Bo Welch, their sons Matthew and Luke, and six siblings. For her family, the confirmation of her cause of death closes one chapter of uncertainty while opening another of remembrance.

For millions who grew up watching her characters and laughing at her performances, Catherine O’Hara’s legacy remains vivid. Her death may have come suddenly, but her work endures, sharp, joyful and unforgettable