Speaking of her nomination, Jennifer said in a statement: "This is the best 6:00am wake up call ever.
"Words can't describe how blessed I feel to be recognized like this by my peers for this film. What an enormous feeling of joy and gratitude."
The 45-year-old has already received rave reviews at the Toronto Festival, where the cast were given a standing ovation, apparently reducing Jen to tears.
British actor Benedict Cumberbatch has also got lots to look forward to, having been nominated twice - once for Male Lead for The Imitation Game and also for Male Actor in a TV Movie or Miniseries, for his work in BBC drama Sherlock.
He revealed: "I'm over the moon. And so delighted to receive recognition in such esteemed company for both Sherlock and The Imitation Game by my acting peers. What an amazing early Christmas present! Thank you to all who voted and watched both pieces of work."
It will be the battle of the Brits when the SAG awards are televised in January, with Benedict also going up against Eddie Redmayne for his stunning performance in The Theory of Everything, playing the inspirational scientist Stephen Hawking.
Eddie is nominated along with his co-star Felicity Jones, and said in a statement: "To be nominated by my peers, and to be included in a list that is comprised of so many actors I admire, is an incredible honor.
"And to be recognized alongside Felicity and my castmates means the world."
Other nominees for Male Actor are Steve Carell for his daring turn in Foxcatcher, Michael Keaton for Birdman, and Jake Gyllenhaal for Nightcrawler, with Keira Knightley, Emma Stone, and Meryl Streep three of the nominated Female Supporting Lead.
The Imitation Game, Boyhood, Grand Budapest Hotel, The Theory of Everything, and Birdman all have been nominated for Outstanding Performance by a Cast in a Motion Picture, while Downton Abbey, Game of Thrones, and Homeland for Outstanding Performance by an Ensemble in a Drama series.