The Colombia striker moves to Old Trafford on a £6m temporary deal from Monaco until the end of the season.
Here is a selection of our favourite tweets from the professionals, past and present, to Falcao’s glamour move.
England legend Gary Lineker (@GaryLineker) is questioning Louis van Gaal’s transfer strategy: “WHAT THE FALCAO?? If you can’t defend just out score ’em!”
Former United midfielder Keith Gillespie (@KeithGillespie7) is excited by the signing: “Falcao on loan! Wow he has some goal scoring average. Another great asset for Manchester United.”
Dexter Blackstock (@dexblackstock23) is left staggered by the wages which Falcao will receive: “So Man U are paying the full 350k a week of Falcao wages and a 12m loan fee for 1 season. The money is going crazy in football”
United legend Philip Neville (@fizzer18) couldn’t resist staying up: “Right transfer deadline done let’s concentrate on the football now please – I’m off to bed knackered hope u enjoyed the night! Changed my mind I ain’t going to bed till falcao is announced!”
The man-of-the-moment Radamel Falcao (@FALCAO) is thrilled to seal a move to the Red Devils: “Moving to @ManUtd was my decision. It’s exciting to play at the world’s best club and in such a competitive league.”
Finally, Reading striker Adam Le Fondre (@A1F1E9) thinks chief executive Ed Woodward has earned his stripes: “Ed Woodward defo walking round OT like cantona after the goal against Sunderland!! #chestout #saywhatnow #dimaria #falcao #mufc”
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news