The actress also uploaded a video of herself to make the announcement, and said: "Last year in lockdown while all of you were learning how to bake... I have written a cheeky little memoirs book."
"It’s called 'Acting Up' and it’s just a little bit about my life from when I was very, very young to now," she explained.
'Acting Up' will be released on November 2 this year, published by Echo Publishing, with Lynne revealing the cover with her fans.
According to Allen & Unwin's website, 'Acting Up: Me, Myself & Irene' is a "warm, hilarious and intimate look inside the life of one of Australia's living TV legends".
"With humour, honesty and self-deprecating charm, one of Australia's best known TV actresses lifts the lid on life - both on-screen and off."
The book's description also notes that Lynne's story will include an Aussie childhood full of "fad diets (tuna, milk and oranges, anyone?)" to the relationship heartaches, career disasters and difficult choices that would "change her life forever".
Lynne's fellow Home and Away co-stars and friends couldn't be more excited for the book, and took to the comments under her post to share their support.
"Cant wait to read it, is there anything you cant do," Johnny Ruffo penned.
His girlfriend Tahnee Sims was right behind him and commented: "So awesome! Can’t wait to read."
"Best bloody book I’m ever going to read!" Courtney Ally said.
Emily Weir added: "OMG AMAZING Lynne! Can’t wait xx"
"I’ve been very lucky to get a sneak peek at this book and it’s awesome!! So proud @lynnemcgranger and I can’t wait for everyone to read it," Ada Nicodemou wrote.