Traveling with the first lady, Melania, and his four adult children, the U.S. president will also attend ceremonies in Portsmouth and Normandy marking the 75th anniversary of the World War II allies' D-Day invasion.
Just like his previous trip to the U.K. last year, Trump has again tested the resolve of May by telling a newspaper that Conservative lawmaker Boris Johnson would be an "excellent" prime minister.
May, who announced her resignation last month after repeatedly failing to win support for a deal under which Britain would leave the European Union, is set to leave office on June 7.
Here's a look at what Trump is scheduled to do over the next three days:
Trump's second visit to Britain will be an official state visit, which means the trip will be a bit different than the previous one.
A state visit is when a head of state visits a foreign country at the invitation of its own head of state, which in this case is Queen Elizabeth II. It usually lasts several days and includes various ceremonies around the country.
The Trump family begin their trip Monday with a ceremonial welcome in the Buckingham Palace garden. There, they met with Queen Elizabeth II, the Prince of Wales, and the Duchess of Cornwall as they inspected the Guard of Honor.
Royal gun salutes were fired in Green Park and at the Tower of London on the River Thames shortly afterward.
The president and his wife attended a private lunch at the palace with the queen, before touring a special exhibition in the picture gallery.
Later in the afternoon, they will head to Westminster Abbey with Prince Andrew to lay a wreath at the grave of the Unknown Warrior.
For afternoon tea, Trump and the first lady will head to Clarence House with Prince Charles and his wife Camilla.
The first day will conclude with a state banquet at Buckingham Palace, where the queen and Trump will be expected to make speeches.
Trump will join May for breakfast at St. James's Palace in London. The Duke of York, as well as other prominent U.S. and U.K. business leaders, will be expected to attend.
Trump and May will hold bilateral talks at 10 Downing Street later in the day, before hosting a joint press conference.
Ahead of Trump's visit trip, political analysts questioned just how deeply Trump would immerse himself into the Conservative Party leadership contest.
He told reporters in an impromptu exchange at the White House before traveling to London that he might meet with Johnson — currently seen as the bookmakers favorite to replace May — as well as Brexit Party leader Nigel Farage.
The U.S. president described them both as "friends" and "good guys."
On Tuesday evening, Prince Charles and Camilla will join the U.S. president and first lady at Winfield House in Regent's Park, the official residence of the U.S. ambassador to the U.K.
Trump's final day in the U.K. will be spent commemorating the 75th anniversary of the D-Day landings.
The president will accompany members of the British royal family at an official event in Portsmouth, before traveling to Normandy to attend another D-Day ceremony in France with President Emmanuel Macron.