The Iron Man star was devastated when Bruce Paltrow passed away in 2002 following a battle with oral cancer, while he was in Rome, Italy celebrating his daughter's 30th birthday.
And the actress admits this year's holiday is particularly poignant for her and her family.
She writes in her Goop.com newsletter, "I dedicate this Thanksgiving letter, on parental acceptance, to my father, who would have been 66 today. He was the greatest parent, friend, rabbi any girl could ever have asked for. Happy Birthday Bruce. And Happy Thanksgiving everybody."