The Mall was decorated with the Spanish flag and the Union Jack ahead of the three-day state visit designed to ephasize strong ties between the two kingdoms.
It is the first State visit by the Spanish royal family since King Juan Carlos visited in 1986.
The Life Guards, members of the household cavalry led the parade up The Mall to Buckingham Palace.
King Felipe and Queen Letizia were greeted by the Prince of Wales and Camilla, Duchess of Cornwall. One kiss or two?
King Felipe and Queen Elizabeth are distant cousins as both descended from Queen Victoria.
Queen Letizia was a journalist and news presenter when she met the future King. She wore a yellow coat-dress by one of her favourite designer's Felipe Varela.
The Spanish couple were formally greeted by the Queen and the Duke of Edinburgh on Horse Guards Parade before travelling up the Mall to Buckingham Palace where they had a private lunch.
It is expected to be 96-year-old Philip's last state visit before he retires from public duties in the autumn.
King Felipe suceeded to the throne in June 2014 after his aging father King Juan Carlos abdicated.
The Spanish King will make a speech to the British parliament this afternoon in which he is widely expected to mention the prickly subject of Gibraltar, a perennial thorn in the side of Anglo-Spanish relations and an issue that has promises to be at forefront of Brexit discussions between the two nations.