Michelle Keegan, 27, wrote: "Thinking about you not just today but every single day.
"I told you Grandma, you're with me. I feel you because I am you."
Michelle added a sweet 'Happy Birthday' to the message to her late grandmother, and a kiss.
Michelle's beloved grandmother, Beth Turner, died of ovarian cancer in 2009.
She revealed in an interview in 2010: "I’m not a big cry baby and I tried to push what was happening to Gran out of my mind when I was working.
“But when I had to cry for the cameras I only had to think about what was happening to her and I couldn’t stop the tears…
“It was such a massive shock when Gran was diagnosed. I panicked and thought she might die. I felt so sick when my mum rang to tell me.
“I just wanted to be with her.”
MARK WRIGHT RIDICULED FOR STRICTLY TEARS: "WHY IS HE ALWAYS CRYING"
Michelle also added that since her Gran’s death, she’s become proactive in raising funds and awareness of the disease.
She said, “I know that cancer doesn’t need to be a death sentence, but with ovarian cancer you need to know you’ve got it before it’s too late.”
Michelle is reportedly planning to enter the I'm A Celebrity 2014 jungle on 16th November - we wil just have to wait and see if rumours prove to be true.