Gifford and Philbin worked together on Live! With Regis and Kathie Lee from 1988 until 2000.
Gifford took to social media to express her sadness over Philbin's death, writing, "There are no words to fully express the love I have for my precious friend, Regis. I simply adored him and every day with him was a gift."
"We spent 15 years together bantering and bickering and laughing ourselves silly—a tradition and a friendship we shared up to this very day," she continued, adding that she smiles knowing that he is in heaven and that at this moment "he's making someone laugh."
"It brings me great comfort knowing that he had a personal relationship with his Lord that brought him great peace," she continued. "I send all the love in my heart to Joy, to his children, to the rest of his family and to the innumerable people he touched over his legendary life. There has never been anyone like him. And there never will be."
Gifford and Philbin worked together on Live! With Regis and Kathie Lee from 1988 until 2000, when Gifford left the show. The two friends kept in touch following their time on the daytime talk show. Philbin and Gifford reunited on Today with Kathie and Hoda, where he made several guest appearances.
The two were photographed out to dinner in January 2018. The pals were all smiles as they dined at Craig's in West Hollywood.
Philbin's family said in a statement to ET: "We are deeply saddened to share that our beloved Regis Philbin passed away last night of natural causes, one month shy of his 89th birthday. His family and friends are forever grateful for the time we got to spend with him – for his warmth, his legendary sense of humor, and his singular ability to make every day into something worth talking about. We thank his fans and admirers for their incredible support over his 60-year career and ask for privacy as we mourn his loss."
In addition to being part of the successful morning show, Philbin also hosted the inaugural seasons of Who Wants to Be a Millionaire and America’s Got Talent. He went on to helm a short-lived revivals of the game shows This Is Your Life, and Million Dollar Password.
Speaking on the transition from morning to prime time Philbin once told The New York Times that the change in schedule marked a turning point.
“That was the highlight of my life,” he revealed. “I realized there was a difference between a syndicated morning show and prime time. ‘Regis saved the network!’ I used to walk around saying that. I was a big man! I was a giant! It was a wonderful time in a broadcaster’s life to get a show like that. Wow, it was dynamite."
He made cameos in Miss Congeniality 2, Shrek the Third, Seinfeld, 30 Rock, How I Met Your Mother and The Simpsons, among other TV shows and films. ET spoke with Philbin and his daughter, J.J. Philbin, in April when he guest starred on Single Parents. J.J. was co-creator and executive producer of the short-lived ABC comedy.
Watch the video below to see our final interview with the TV icon.