The young royal was snapped showering Kate with kisses and cuddles while sitting on her lap to watch the epic carnival procession.
WATCH: Prince Louis having fun with Prince William, Kate and Prince Charles at the Jubilee Pageant
The parade marked the closing of the four-day celebration which honoured the Queen's remarkable 70 years on the throne.
Featuring giant puppets, the Gold State Coach, and a host of celebrities, the event saw the very best of music, theatre, street arts, carnival and costume join together to celebrate the monarch.
Kate and Louis were snapped sharing a sweet moment
While the Queen was absent for most of the Pageant, she delighted fans with a brief appearance on the Buckingham Palace balcony at the end of the event. Her arrival came after an emotional performance from pop star Ed Sheeran, who sang his chart-topping ballad Perfect as a video montage featuring clips of the Queen from over the years played.
Fans were particularly pleased to see the monarch as she was unable to attend Friday and Saturday's events after experiencing "some discomfort" during Thursday's celebrations, meaning she missed the Party at the Palace concert at Buckingham Palace as well as the Epsom Derby, which took place on Saturday.
The royals were all smiles as they closed the Pageant with their balcony appearance
Prince Louis' sweet moment with his mum comes just days after he was captured pulling faces while appearing on the balcony during the military flypast at Trooping the Colour on Thursday.
The young prince was seen happily waving towards the sky before later holding his hands over his ears as the aircraft flew overhead, at which point Kate was pictured bending down to have a word with him.
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