Billie Lourd attends the "Booksmart" New York screening at the Whitby Hotel on May 21, 2019 in New York City. (Dia Dipasupil/Getty Images)

American Horror Story actor Billie Lourd, the granddaughter of the late Debbie Reynolds, is set honour the star on Will and Grace.

Reynolds, who passed away in 2016, famously played Grace Adler’s (Debra Messing) mother Bobbi on the show.

The actor, who was also the mother of the late Carrie Fisher, shot to fame when she played Kathy Selden in the 1952 film Singin’ in the Rain.

“I have watched and loved Will and Grace since I was (probably too) young,” Lourd posted on Instagram on Thursday, September 20.

“So getting to watch my grandma play Grace’s mom was one o’ the coolest things to happen to my young willandgraceobsessed self.

“Next week I get to play my real life grandma’s on screen granddaughter on one of my favourite shows and there are not enough happy adjectives in the world to convey the excitement I feel.”

As well as playing the role of Winter Anderson in American Horror Story, Lourd, 27, also played the character Gigi in the coming-of-age 2019 film Booksmart, which has been praised by LGBT+ fans for its queer themes.

Billie Lourd to play Grace’s niece Fiona as tribute to grandmother Debbie Reynolds.

Lourd is set to take up the role of Grace’s niece Fiona, and it will see her character reconnecting with her “cool” aunt, according to Deadline.

Speaking about Lourd’s role, Will and Grace co-creator Max Mutchnick told Deadline: “The episode is especially meaningful because of Billie’s relationship to the show.

“We’re thrilled to have Billie. And best of all — she’s really good.”

Will and Grace: A pioneering show for LGBT+ rights.

Will and Grace and its cast have a long history of advocating for LGBT rights, long before it was commonplace.

Two of the series’ main characters – Will Truman (Eric McCormack) and Jack McFarland (Sean Hayes) – are openly gay.

Next week I get to play my real life grandma’s on screen granddaughter on one of my favorite shows and there are not enough happy adjectives in the world to convey the excitement I feel.

Former US vice president Joe Biden even credited the show with changing America’s views on LGBT+ people.

The show originally ran for eight seasons from 1998 to 2006 on NBC.

It was revived by NBC in 2017 for three more seasons, with the series paying tribute to Reynolds.

The relaunched series featured stars from the original cast, including Debra Messing, Eric McCormack, Sean Hayes and Megan Mullally, along with the show’s creators Max Mutchnick and David Kohan.

The eleventh and final season of Will and Grace is set to air this autumn.