Taking to Instagram, McKenna, who is currently filming for Peaky Blinders, wrote: “I can’t tell you how much I looked up to #helenmccrory as an actress. I FEASTED on her performances and I know her legacy lives ON.
“I can’t say I knew her as a friend but my sadness at her passing is no less valid. We’ve lost a giant. Today was a very strange and sad day on set. And my heart goes out to everyone.”
Meanwhile, Normal People star Sarah Greene wrote a heartwarming tribute to the late Peaky Blinders star.
She shared two snaps of the pair together, both on and off screen.
Sarah wrote on Instagram: "It was an honour and a privilege to have worked with and known this force of nature.
"Absolutely heartbroken for Damien and her family. Shine bright you almighty star."
Other Irish actors including Cillian Murphy and Aisling Bea have joined the showbiz world in mourning the passing of “gifted” McCrory.
“Peaky Blinders” star Murphy described McCrory who played Polly Gray, the aunt of his character Tommy Shelby as a compassionate friend and fearless actor.
“I am broken-hearted to lose such a dear friend,” Murphy said. “Helen was a beautiful, caring, funny, compassionate human being. She was also a gifted actor — fearless and magnificent.
“She elevated and made humane every scene, every character she played. It was a privilege to have worked with this brilliant woman, to have shared so many laughs over the years. I will dearly miss my pal. My love and thoughts are with Damian and her family.”
Aisling Bea, who also starred with McCrory in the 2020 ITV drama Quiz, said: "Utterly heartbreaking, what a loss. Every actor looks & looked up to Helen McCrory – so brilliant and gripping and transformative and those who knew her as a friend really loved her.
"On Quiz last year & she was just so bloody cool, with funny anecdotes & stories and worrying about remembering all her lines.
"I could not believe that THE Helen McCrory was pacing up & down, worried about lines, she was so down to earth & openly vulnerable, all for the craft & being as good as possible.
"Then we watched her in the courtroom pretty much do a one-woman monologue and be incredibly excellent and not forget a thing. #RIPHelenMcCrory Thoughts go out to her family and friends."
Both stars added their tributes to those paid by numerous other famous names including James Bond producers Michael G Wilson and Barbara Broccoli who said in a statement they are “devastated” by the death of the “extraordinarily talented and gracious” actress.
Dame Helen Mirren wrote on Instagram: “A great actress and a great person. this is so very very sad.”
William Russell, Lord Mayor of the City of London and the half-brother of Lewis, said: “We will all miss my sister-in-law Helen McCrory.
“I have many fond memories of her. A huge loss to my family as well as to British acting. Thank you for the messages of condolence and sympathy which people have sent.”
Comedian Matt Lucas, who worked with McCrory on the FeedNHS campaign to supply food for NHS staff amid the pressures of the Covid-19 pandemic, said: “She and Damian were the motor driving FeedNHS, working tirelessly during the pandemic to raise millions for others. What a tremendous loss.”
“Helen McCrory will be remembered not just for her remarkable stage and screen performances, but also for her selflessness and generosity.”
“She and Damian were the motor driving FeedNHS, working tirelessly during the pandemic to raise millions for others. What a tremendous loss.”
Comedian John Bishop, who starred alongside McCrory in ITV drama Fearless, tweeted: “I am shattered to hear this news. Helen was a beautiful supportive person to those of us who had the honour to know or work with her. The world has just lost some of its sparkle.
“My heart goes out to Damian and the family, no words of condolences will ever be enough.”
Paying tribute to McCrory, Mayor of London Sadiq Khan recalled her help in unveiling a statue of Millicent Fawcett, where McCrory performed an adaptation of one of the suffragist leader’s speeches.
“So sad to hear this news. Helen McCrory was an unparalleled talent and made a difference to many young Londoners through her charity work,” Mr Khan tweeted.
“I have fond memories of her helping us unveil the statue of Millicent Fawcett in Parliament Square. Sending love to her family.”
The Wizarding World Twitter account, home to the Harry Potter franchise, tweeted: “We are deeply saddened to hear of the passing of our beloved Helen McCrory, who played Narcissa Malfoy with such depth and brilliance in the Harry Potter film series.
“She was a wonderful actor and a very dear friend; Harry Potter fans will miss her very much.”