Trump is due to meet Prime Minister Theresa May on July 13 reports the BBC.
Campaigners raised almost 18 000 pounds for the helium-filled six-metre high figure which they said reflects Trump s character as an "angry baby with a fragile ego and tiny hands".
London Mayor Sadiq Khan gave permission for the balloon to fly.
A statement on behalf of Khan said that he "supports the right to peaceful protest and understands that this can take many different forms".
Khan s city operations team met organisers and gave them permission to "use Parliament Square Garden as a grounding point for the blimp".
Under the plans the balloon will be allowed to fly at Parliament Square Garden for two hours on the morning of July 13.
--IANS ksk/sac