Christina Hendricks has revealed it's her hand on the iconic 'American Beauty' movie poster.

Christina Hendricks

Christina Hendricks

The former 'Mad Men' actress drew a surprised response from her fellow celebrities when she shared the "fun fact" 20 years after the movie's release.

Christina also revealed that she worked as a hand model and that the stomach her hand is placed on is someone else's.

Alongside the poster - which is a close up of a rose being placed on the stomach - she wrote on Instagram: "Fun fact.... wait for it...I used to be a model and sometimes a hand model.... this is my hand and another model's stomach....proud to be a part if this film in ANY WAY!!! #americanbeauty (sic)"

Many would have presumed that actress Mena Suvari - who played Angela Hayes in the Sam Mendes drama - was featured on the poster.

Among those taken back by the revelation was Christina's former 'Made Men' co-star January Jones.

She wrote in the comments under the post: "This is important. How come I didn't know this?"

Actress Elle Fanning responded: "IM SHOOK!!!!!!."

'Dawson's Creek' star Busy Philipps wrote: "Wait.... What!?"

Stand-up comedian Whitney Cummings was just as stunned.

She wrote: "This is blowing my mind."

And 'Glow' star Alison Brie added: "WHOA."

The 1999 classic swept the board at the 2000 Oscars, winning Best Picture, Best Actor for Kevin Spacey, Best Director, Best Original Screenplay and Best Cinematography.

Since 'American Beauty', Christina has gone on to have a number of surprising jobs, including voicing the commercials for Baskin-Robbins ice cream since 2012.

The 44-year-old actress currently stars as criminal Beth Boland in NBC's comedy-drama 'Good Girls'.