The birthday message signed off with a reminder the 2021 season of the show is set to return next week.
"#HomeandAway returns February 1. 7PM on @channel7 #SummerBay #summerbaycast #aussiedrama #tvdrama #aussietv #tvseries #mustwatch."
Lynne's co-star Rob Kipa Williams, who plays Ari Parata on the show, was quick to comment on the post to wish his co-star a happy birthday.
"Happy Birthday @lynnemcgranger," he wrote.
For nearly three decades, Irene Roberts has been the heart and soul of Home And Away.
Loved across the globe, the popular character is known for her welcome presence, warm heart and quick-witted remarks. Not to mention, her turbulent life in Summer Bay.
Opening about the fate of her character, Irene told Perth Now last year that while there was no dramatic death on the cards just yet, if it were to happen she would want it to be a tear-jerker event.
"There is no scheduled death for her as far as I know yet, but when I go I want her (Irene) to die what I call a Molly death, as in A Country Tradition,'' she said, in reference to one of Australian television's most heartbreaking deaths when Molly Jones died after a battle with leukemia on A Country Practice.
"She closed her eyes, and the black vanished. The entire world afterward was in rehabilitation… I'd love such a tear-jerker," Lynne explained.
But for the actress who portrays the character, it's a life far removed from her own. Unlike her alter-ego, the star prefers to keep a low profile and is a devoted mother to her adult daughter Clancy and loving partner to Paul McWaters.
"Aside from being a wonderful man, if it wasn't for him I'd never have been able to do what I've done on Home And Away. He took over as a house husband and primary carer of Clancy," Lynne revealed to Woman's Day.
"He's amazing. We still enjoy each other's company and still make each other laugh."
This article first appeared on our sister site Now To Love.