Catherine O‘Hara’s Cause of Death Reveals Private Cancer Battle With a Pulmonary Embolism

According to her death certificate, the actress died on Jan. 30 from a life-threatening blood clot with rectal cancer being listed as the underlying cause.

Catherine O'Hara, a cast member in the Apple+ series "The Studio," poses for a portrait in Los Angeles on March 20, 2025. Chris Pizzello/AP Photo

The cause of death of Emmy award-winning actress Catherine O’Hara was revealed to be a result of a pulmonary embolism while battling cancer.

According to her death certificate from the Los Angeles County Medical Examiner’s Office, O’Hara died on Jan. 30 at the age of 71, with rectal cancer being listed as the underlying cause.

A pulmonary embolism is a life-threatening clot that restricts blood flow to the lungs and reduces oxygen levels. Symptoms include shortness of breath or chest pain, and it requires immediate medical attention.

The oncologist listed on the certificate indicated O’Hara had been receiving treatment since March of last year. She was last seen by the doctor on Jan. 27, before she died at a hospital in Santa Monica, California.

Rectal cancer is a type of colorectal cancer and is the third-most common cancer in the United States, according to the Cancer Center. It occurs when cells mutate and form in the tissue of the rectum.

Per her death certificate, O’Hara was cremated and her remains were given to her husband of over 33 years, Bo Welch.

At the time of her passing, her representatives at the Creative Artists Agency said O‘Hara died at her home in Los Angeles “following a brief illness” without providing further details.

The Canadian-born comic actor launched her career with the Second City comedy group in Toronto in the 1970s. Alongside lifelong collaborator and her “Schitt’s Creek” co-star, Eugene Levy, the two were original cast members on the “Second City Television” series in 1976.

With a resume that spanned over 50 years, O’Hara went on to hold memorable roles in blockbuster hits like Martin Scorsese’s 1985 “After Hours,” Tim Burton’s 1988 “Beetlejuice,” which she went on to reprise in the 2024 sequel, and two “Home Alone” films in the 1990s.

In 1982, O’Hara earned her first Emmy nod for her writing on SCTV and in 2020 the award for Outstanding Lead Actress in a Comedy Series for her leading role in “Schitt’s Creek.”

News of her death sent shock waves across Hollywood, with co-stars, friends, and industry professionals alike paying tribute in heartfelt social media posts.

“Mama. I thought we had time,” Macaulay Culkin, who played O’Hara’s son in “Home Alone,” wrote on Instagram. “I wanted more. I wanted to sit in a chair next to you. I heard you. But I had so much more to say. I love you. I’ll see you later.”

“Words seem inadequate to express the loss I feel today,” said Levy in a statement. “I had the honor of knowing and working with the great Catherine O’Hara for over fifty years.”

“From our beginnings on the Second City stage, to SCTV, to the movies we did with Chris Guest, to our six glorious years on Schitt’s Creek, I cherished our working relationship, but most of all our friendship. And I will miss her.”

She is survived by Welch, sons Matthew and Luke, and siblings Michael O’Hara, Mary Margaret O’Hara, Maureen Jolley, Marcus O’Hara, Tom O’Hara, and Patricia Wallice.

The Associated Press contributed to this report.