Buckingham Palace confirmed Philip's attendance on Friday. The 96-year-old underwent a planned hip operation in April.
Philip has been recovering at Windsor Castle, near St. George's Chapel, where Harry and Markle will tie the knot. He was spotted for the first time since his surgery last week alongside his wife, Queen Elizabeth II.
Philip retired in August after 65 years of service.
The royal wedding begins Saturday at noon GMT, 7 a.m. EST.
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