Modern Family has cast TV's youngest transgender actor. Meet eight-year-old Jackson.

You’ve probably never heard of the newest Modern Family cast member. But at eight-years-old, actor Jackson Millarker is about to make history.

The reason? He’s transgender.

It’s believed the Atlanta school boy is the first openly trans child to be cast in a prime-time US series.

He will play Lily’s friend in an upcoming episode of the juggernaut sitcom titled “A Stereotypical Day”. According to Variety, the plot will go a little something like this:

Lily’s parent’s Cameron (Eric Stonestreet) and Mitchell (Jesse Tyler Ferguson) burst with pride that they have raised a child that would be so accepting and open-minded to have a transgender friend. Until, that is, they overhear her insulting him. Cue teachable moment.

The episode’s director Ryan Case introduced him on Instagram.

He might be the youngest, but Jackson is certainly not the only transgender star of a popular television show.

Laverne Cox was nominated for an Emmy for her role on Orange is The New Black and later this year will make history as the first trans actor in a leading role when she stars in the upcoming series, Doubt.

Laverne Cox in Orange is the New Black. Image: Netflix.

The folks behind Nashville have also cast Jen Richards in a recurring role for the fifth season.

Still, Transparent actor Jeffrey Tambor pointed out at the Emmy Awards just last week, there's still a long way to go.

The Best Actor winner, who stars as trans character Maura Pfefferman in the hit show, said he would not be unhappy to be last cisgender man to play such a role.

"To you people, you producers and network owners, agents and creative sparks," he said during his acceptance speech. Please give transgender talent a chance. Give them auditions. Give them their story. Do that.”

Modern Family has, and they're being widely applauded for it. As well as earning headlines around the world, it's being hailed as critical step on social media.

Congrats Jackson. Can't wait to watch the episode.