The 22-year-old winger became manager Pardew's fifth summer signing after he put pen to paper on a five-year deal at St James' Park.
After passing a medical on Tyneside, the winger is expected to go straight into the first team for this weekend's opening Premier League fixture at home to Arsenal.
Done deal: Gabriel Obertan has completed his move from Manchester united to Newcastle
Obertan joined United in July 2009 with high hopes from Bordeaux but failed to establish himself in Sir Alex Ferguson's side, making a total of 28 appearances and scoring just one goal for the Old Trafford club.
But boss Pardew, who drafted in the former Clairefontaine academy product to add pace to his team as a replacement for Wayne Routledge, insists Obertan can have a real impact in the top flight.
'Gabriel is a player I've watched for the last couple of seasons since he arrived at Manchester United,' Pardew told the club's official website.
High hopes: Toon boss Pardew expects new signing Obertan to hit the ground running
'He has great pace and excellent technique and he has improved his power in the last 12 months and is ready now to make a real impact in the Premier League.
'I contacted Sir Alex about him early at the start of the summer to see if there was an opportunity to bring him to Newcastle, but it wasn't until Wayne Routledge joined Swansea that we were able to bring him in.
'His best years are ahead of him which is exactly what we want at this club, and with the backing of our magnificent fans I'm sure he will prove an excellent signing for us.'
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