Neymar, 25, who was presented to PSG fans at the Parc des Princes stadium, said he was "very happy" to have joined the club and even spoke in French.
"Thank you! I’m very happy, I’m delighted to be here for this new challenge," said Neymar as fans chanted his name over and again.
"I want to win lots of trophies with you and I need your support to win these trophies.
"Paris is magic!"
Neymar fever has swept through Paris since he joined the club, with more than 1,000 fans queuing to buy a jersey of their new number 10 at PSG's Champs-Elysees shop on the day he signed.
And even the Eiffel Tower got in on the act - welcoming the star Brazilian by shining his name on the city's famous landmark.