The 20-year old Spanish goalkeeper has finally made the much talked about switch from Atletico Madrid to the English champions, signing a five-year deal.
The signing has been welcomed by Ferdinand who was delighted that the Old Trafford club had made another top signing.
"David de Gea, welcome bro! Another quality young player signed. Manchester United have had a nice bit of movement in this transfer window!
"De Gea has got nice feet too. I love that in a keeper,” he wrote on his Twitter page.
The signing of de Gea comes after Sir Alex Ferguson secured the services of Phil Jones from Blackburn Rovers and Ashley Young from Aston Villa in what has already been a busy summer for the champions.