The Duke and Duchess of Cambridge will join the Queen and Charles and Camilla for the event.
Buckingham Palace has released the itinerary for the President's three-day visit to the UK today, which will include a visit to Downing Street for talks with Prime Minister Theresa May, who yesterday announced her resignation.
In 2016, then-Suits actress Meghan Markle campaigned against Trump becoming president and backed Hillary Clinton for president.
"I'm voting for Hillary Clinton, not because she is a woman, but because Trump has made it easy to see that you don't really want that kind of world that he's painting," she said at the time.
Trump's daughter Ivanka and her husband Jared Kushner, both advisers to the President, will reportedly join the President and Melania Trump in the UK, along with his other adult children, Tiffany Trump, Donald Trump jnr and Eric Trump.
After his lunch with the Queen and Prince Harry, Trump, accompanied by Prince Andrew, will visit Westminster Abbey, where he will lay a wreath at the Grave of the Unknown Warrior.
In the evening, The Queen will host a State Banquet at Buckingham Palace and Her Majesty and the President will make speeches.