The one-hour special will look at how the film became a beloved Christmas tradition and a global sensation, with exclusive interviews with cast members.
Hugh Grant, Dame Emma Thompson, Bill Nighy, Laura Linney and Thomas Brodie-Sangster will sit down with ABC News anchor Diane Sawyer for the show.
It will also include an appearance from writer and director Richard Curtis, as well as a message from Martine McCutcheon.
ABC said the special would offer new insight into behind-the-scenes secrets and the film’s famous scenes as well as examining how the Covid-19 pandemic “refocused the ways we love and connect”.
In an exclusive clip of the interview, Dame Emma recalled watching the film for the first time.
“Hugh came up behind me as we were walking out and said ‘is that the most psychotic thing we’ve ever been in?'” she said.
Grant, who plays the British Prime Minister in the iconic Christmas film, also reveals he thought he would “hate” the iconic dancing scene in Downing Street.
“But I will give myself the credit of having the secretary catch me,” he says.
In another clip, Curtis tells Sawyer: “I do think that the way to think about life is that every day has the potential just to be gorgeous.”
Sawyer also poses the ever elusive question to cast members: “Love actually is?”, to which Grant answers “dead”.
The special comes after cast members in 2017 reunited for the short sequel, Red Nose Day Actually, which was also made by Curtis and further developed key character storylines.
Several scenes from the short echoed iconic moments from the film such as the cue card scene with Keira Knightley’s and Andrew Lincoln’s characters.
In the mini sequel, Grant, Liam Neeson, Linney, Colin Firth and Rowan Atkinson made appearances.
Curtis, who was also involved in Four Weddings and a Funeral and Bridget Jones’ Diary as a writer, said in the lead-up he would “never have dreamt of writing a sequel to Love Actually”, but added: “I thought it might be fun to do ten minutes to see what everyone is now up to.”
“We’ve been delighted and grateful that so many of the cast are able to take part – and it’ll certainly be a nostalgic moment getting back together and recreating the characters 14 years later,” he said.
“We hope to make something that’ll be fun – very much in the spirit of the original film and of Red Nose Day – and which we hope will help bring lots of viewers and cash to the Red Nose Day shows.”
Love Actually has consistently rated as the top searched-for Christmas film in France, Italy and 17 other countries, totalling 887,000 worldwide searches a month.
The story of the original film, which is an international co-production between the UK, the United States and France begins five weeks before Christmas and is played out in a weekly countdown until the holiday, followed by an epilogue that takes place one month later.
The Laughter & Secrets of Love Actually: 20 Years Later – A Diane Sawyer Special, will air on Wednesday, November 30 at 1am UK time on ABC.