The Billions actor read a poem by Irish writer Derek Mahon titled Everything is Going to be All Right at the A Poet For Every Day Of The Year event at London's National Theatre.
According to the Mail Online Lewis, 50, said: "This evening is dedicated to her and it's perfect, because Helen loved the National Theatre. One person whose thunder would absolutely not be stolen was Helen McCrory."
McCrory's children she shared with the Homeland star — daughter Manon, 15, and son Gulliver, 14 — were in the audience, along with actors including Simon Russell Beale, Lesley Sharp, Fay Ripley and Danny Sapani.
Lewis read Mahon's poem which includes the lines: "There will be dying, there will be dying/but there is no need to go into that."
It ends with the phrase: "Everything is going to be all right."
Lewis is reported to have had his eyes closed throughout the video.
Writer Allie Esiri, who was hosting the event, said: "We dedicated the evening to Helen, and Damian said a few words, but we just wanted to get on and do the show.
"It's what she would have told us to do – 'OK, enough already, get on with the show!'
"She loved poetry and I think she would have been pleased to be kind of here with us. It felt right."
He confessed: "Already I miss her. She has shone more brightly in the last months than you would imagine even the brightest star could shine."
McCrory was awarded an OBE in 2017 for services to drama, and recently had been raising money for the Feed NHS charity, raising £1m in 2020.
After studying acting at the Drama Centre in London, she made her film debut in 1994's Interview With The Vampire, and has many film roles to her name including Narcissa Malfoy in the Harry Potter film series, Cherie Blair in The Queen, and MP Clair Dowar in the 2012 James Bond film Skyfall.
Her TV roles include Polly Gray in the BBC's Peaky Blinders, Madame Kali in Penny Dreadful, and more recently Sonia Woodley QC in the TV drama Quiz.
Lewis and McCrory married in 2007.
Watch: Helen McCrory kept her illness a secret right up until her death