The 23-year old centre-back has signed a five-and-a-half-year deal from Montpellier for a reported fee of around £7million and Pardew was quick to praise the much-needed new addition.
"We needed to strengthen the team and bringing in Mapou will give the whole squad a boost. He is precisely the sort of player we've been looking to bring to the club," he said.
"He is a good age for us but has plenty of experience at club and international level.
"Mapou is a talented footballer, good in the air and on the ground and has all the attributes to succeed as a quality defender in the Premier League.
"He's a good character too and that will be important for us over the next few months."