But it wasn’t boldness alone that made her one of the greats, and her characters memorable: No matter how absurd or how preposterous or even cliche on the page, there was always a beating heart underneath the silliness, a compassion that shone through. Yes, even as Cookie Fleck, with all her ex-boyfriends, in “Best in Show.”

Kevin Nealon said it simply: “She changed how so many of us understand comedy and humanity.”

Because of that innate grasp on her craft, unwillingness to settle into nostalgia and uncanny ability to invent herself anew with each project, her characters would impact multiple generations of film, television and comedy fans. Before she died at age 71, she was still forging new trails as the ousted studio executive Patty Leigh in “The Studio.” And she did it all with grace and humility, a diva only when the role and costume demanded it.

As fellow Canadian Sarah Polley, who she acted with on “The Studio,” wrote on Instagram Friday: “She was the kindest and the classiest. How could she also have been the funniest person in the world?”

Just eight years younger than another comedy trailblazer Gilda Radner, whom she understudied for at “The Second City” in Toronto, O’Hara was not an obvious candidate for stardom as the second youngest of seven in a decidedly non-showbiz, Catholic family. But she loved comedy, obsessing over “Monty Python” in high school and even trying to meet them at the airport once after hearing they were flying in. And when her brother began dating Radner, she followed that trail to the improv stage.

Her first job was not on stage, however, but as a server where she absorbed all that she could. Though she was turned down after her first audition, she wasn’t deterred; She joined the company in 1974. By 1976 she was an essential part of the cast’s transition to television on “SCTV,” where she did original characters and impersonated well-known personalities of the time, including Meryl Streep, who she’d later act alongside.

“My crutch was, in improvs, when in doubt, play insane,” O’Hara told The New Yorker in 2019. “You didn’t have to excuse anything that came out of your mouth. It didn’t have to make sense.”

By the time the show ended in 1984, she was itching for something more, something deeper and started reading scripts for films. Some equated her pickiness (including pulling out of “Saturday Night Live”) with a kind of lack of ambition. For her, it was about waiting for the right thing. Though her film debut was less than auspicious (in the poorly reviewed Canadian thriller “Double Negative” alongside “SCTV” peers like John Candy and Eugene Levy) she soon found her footing working with the likes of Martin Scorsese in “After Hours” and Mike Nichols in “Heartburn,” where she’d play the gossipy beltway journalist friend of Streep and Jack Nicholson.

“You have to try to make this person a real person,” she said in a 1986 CNN interview. “When I first read it, I thought oh this woman does nothing but gossip. But then I started seeing her as a human being, like myself.”

It’s an impulse that served her well during her Hollywood ascent in the late 1980s and early 1990s. You can watch “Home Alone” for the hijinks, but O’Hara made it emotional and grounded as the mom just trying to get back to her child. There was humor, yes (remember the fake Rolex?) but then, a beat later, there were tears. Even Delia Deetz was relatable, giving her husband a withering glare at his tone-deaf suggestion that she might now be able to make a decent meal in her new suburban prison.

She was feisty in period garb as Wyatt Earp’s sister-in-law, sweetly crazy as the depressed, overwhelmed mother to Colin Hanks in “Orange County,” and crazy-crazy as Marty Funkhouser’s sister Bam Bam in “Curb Your Enthusiasm.”

From her perspective, nothing was as big as “Schitt’s Creek,” an unlikely cultural phenomenon that had everyone suddenly pronouncing baby as “bébé” (and it wasn’t because of a sudden French language surge on Duolingo). Few actors get to create their own language and cadence as O’Hara managed to do with Moira Rose.

That unmistakable and unplaceable accent, she told Rolling Stone in 2020, was sort of “in defense of creativity.” She was inspired by women she’d met over the years who, out of insecurity and pride, create new personas whole cloth. As far as the look went, socialite Daphne Guinness was the starting point.

“I think that Canadians have not only a sense of humor about others but about themselves, which I think is the healthiest and best kind of sense of humor to have,” she said in that same Rolling Stone interview. “There’s an edge to it but with a compassion and love.”

Just think about Levy’s Mitch and O’Hara’s Mickey in Christopher Guest’s “A Mighty Wind” singing that mock folk song “A Kiss at the End of the Rainbow” with its saccharine sweet lines. It is ridiculous. It is funny. And it might just make you cry a little too.