William and Kate toured the iconic building after flying in from Bhutan, with the prince describing the building as "stunning and beautiful".
Kate said: "It's been really incredible learning about the romance of the building, it's a really beautiful building."
At one point the pair posed for pictures on the same bench that Diana sat on 24 years ago.
The picture of Diana sitting alone in front of the Taj became a defining image and by the end of 1992 it was announced the couple had decided to separate.
In temperatures of 41C (106F), William and Kate toured the grounds of the Taj and were given a guided tour of the mausoleum itself.
The Cambridges' communications secretary Jason Knauf said: "The Duke of Cambridge is of course aware of the huge esteem his mother, the late Princess of Wales is held in India and he appreciates the status of the images that exist of the Princess at the Taj.
"He feels incredibly lucky to visit a place where his mother's memory is kept alive by so many who travel there.
"Twenty-four years on from her visit to the Taj, the Duke and the Duchess are looking forward to seeing this beautiful place for themselves and creating some new memories as they say thank you to the people of India at the conclusion of this tour."
The Taj Mahal was built by the Mughal emperor Shah Jahan in the mid 17th century, a monument of love to his favourite wife, Mumtaz Mahal.
It took 22 years and 20,000 men to erect the building from white marble transported from 200 miles away by elephants.
The visit brings to an end William and Kate's seven-day tour of India and Bhutan which has seen them not only visit slums in Mumbai and meet Bollywood stars but forge a friendship with Bhutan's Dragon King and his Queen.