Ellen Degeneres is to celebrate 20 years since she came out in a special show this Friday.

The iconic lesbian comic came out on Oprah, as well as in her sitcom, Ellen, back in 1997.

She has now recorded a very special anniversary show looking back at two decades since her coming out, to be joined by Oprah Winfrey and the original cast of the show.

An incredible 42 million people tuned into to watch Ellen come out, one of the most watched TV moments of that year.

For the first time since the sitcom series ended in 1998 – amid anti-gay protests and outrage – the cast will be reunited on this Friday’s show.

According to The Hollywood Reporter: “The Ellen DeGeneres Show will celebrate the milestone with a reunion with special guest stars Oprah Winfrey and Laura Dern joining castmembers Joely Fisher, Clea Lewis and David Anthony Higgins.”

Celebrity fans and followers are due to pay tribute to the out star, too.

Ellen has been a champion for the LGBT community for two decades now, something she was awarded the Presidential Medal of Freedom for by former president Barack Obama.

On her coming out, she said: “I knew that it would be big, but I never knew it was going to be this big.

“I didn’t think it would drag out for so long either,” Ellen told Oprah at the time.

The media circus and interest in the American tabloids surrounding DeGeneres’ sexuality was intense, as she was the first leading character in a television program to be openly gay.

In the summer of 1996, the star called a meeting for the writers of her hit show Ellen, who were about to write Season Four, and told them she wanted her character to come out on the show. “There was concern over not only how the audience would react, but how the advertisers would react,” biographer Lisa Iannucci told Biography.com.

“We had no idea if ABC were even going to allow that to happen,” Ellen’s brother, Vance DeGeneres a screenwriter on the show told biography.com “So it was an incredibly stressful season.”

Watch the moment DeGeneres comes out on her sitcom below.

Ellen decided to come out in real life before her character did on the show, with interviews on The Oprah Winfrey Show, Diane Sawyer and the cover of TIME Magazine.

“It’s something I decided I wanted to do and thought it would be wonderful for me as a result,” Ellen told Oprah at the time.

“I never thought it was anybody’s business, who I am and who I am with. And then I realised since I had this secret that worried me all the time that it made it feel like something was wrong.”

At one point Oprah asks what made Ellen ‘finally comfortable to say it‘ to which Ellen responds, “I’ve become more comfortable with myself just in general and I went to therapy and you know, not for that issue but just finding out more about myself.”

Sawyer even went as far as to ask Ellen whether she’d slept with men.

DeGeneres noted she’d slept with two men in her life and likened the occasions to Peggy Lee’s hit ‘Is That All There Is?’

In the weeks following her character coming out to over 42 million viewers, many religious groups began to protest outside their local ABC stations to take Ellen off air.