Ryan Seacrest's Father Dead at 79

Ryan Seacrest has announced heartbreaking news ... his father, Gary Lee Seacrest, has died following a years-long battle with prostate cancer.

The "Wheel of Fortune" host shared the news on Instagram Friday, telling fans his father "peacefully passed away earlier this week." He said his family finds comfort knowing "he is in a better place and free of any pain or suffering."

He wrapped up his post -- which featured a handful of family photos -- by speaking directly to his late father, writing ... "Dad you will live in our hearts forever. I love you."

Earlier this year, Ryan shared on "On Air with Ryan Seacrest" that his dad had been privately battling prostate cancer for years ... and that the treatment did not help one bit.

RS recalled the ups and downs of his father's cancer journey at the time, revealing he once learned during an episode of "American Idol" that his dad was in the ICU ... and the "life or death conversation" with doctors that followed.

Gary was married to his wife, Marie Zullinger, for 55 years, who survives him, along with Ryan, daughter Meredith Seacrest, her husband Jimmy Leach, and their daughter Flora Leach.

Gary Seacrest was 79.