Meghan Markle makes surprise America's Got Talent cameo

Who knew the former royal's next move would be reality TV? Meghan Markle has made a surprise appearance on a reality show finale. Photo / Supplied

Meghan Markle has stunned fans with a with a surprise appearance on the season finale of America's Got Talent.

The Duchess of Sussex appeared on the reality show via a recorded message to support singer Archie Williams who had previously been wrongly-incarcerated for over 37 years.

"Just wanted to let you know that we've been so moved by your story and we've been cheering you on every week … and it's not just because we're partial to the name," she said in the message.

"Here's a very special message to you, that I'll probably be saying all of my life, but on this night it's specifically for you…"

"Archie, we are proud of you and are rooting for you, we can't wait to see what you do. We're in your corner, have a good night."

Williams went viral during his initial audition – which aired in May – where he performed a rousing rendition of Elton John's hit Don't Let The Sun Go Down On Me.

When asked by head judge Simon Cowell to tell them about himself, Williams shocked everyone by sharing his incredible story to freedom.

He began: "I was just incarcerated for 37 years for somebody else's crime. DNA freed me."

He explained that he was sentenced to 80 years in prison for a crime he didn't commit.

He said: "On the morning of December 9 1982, a 30-year-old white woman was raped and stabbed in her home. I was arrested on January 4.

Archie Williams has captivated with his talent and backstory. Photo / Supplied

"I couldn't believe it was really happening, I knew I was innocent, I didn't commit a crime, but being a poor black kid, I didn't have the economic ability to fight the state of Louisiana.

"At the trial, none of the fingerprints had the same match as mine. Three people testified that I was at home but they wanted somebody to pay.

"I was sentenced to life and 80 years without the possibility of parole or probation."

Archie said that his case was eventually taken by the Innocence Project, who used new technology to prove the fingerprints found at the crime scene matched those of a serial rapist – not his.