And the 26-year-old is delighted with the move.
"When I spoke to my agent, it was a big thing that Arsenal were interested in me," he told the club's website. "This is one of the best clubs in the world, so I'm absolutely delighted to be joining. I'm really looking forward to playing in this jersey and helping my team.
"The conversations started a couple of weeks ago. Arsenal told us that they were interested. We'd just won everything with Flamengo – I won the league and the Copa Libertadores and was also named best centre-back in America, so that will have helped Arsenal notice me.
"It's a great achievement for me to come to Arsenal and it all happened in basically two weeks."
"I'm used to a lot of media interest so I know what to expect when joining a big club like this one. It's a normal thing for me now."
Welcome to London. Welcome to Arsenal.@PabloMV5 is coming to the capital! pic.twitter.com/X07dtNeG5Y
— Arsenal (@Arsenal) January 29, 2020