The Chelsea midfielder has completed his mega deal to Asamoah Gyan's parent club, Shanghai SIPG.
The Black Stars striker who failed to make a mark in the Chines League after joining Shanghai SIPG from Al Ain due to recuring injuries is on a season long loan at Al Ahli Dubai in the United Emirates.
If he shines, he could be recalled to the team to join the likes of Hulk and Oscar at Shanghai SIPG.
The 25-year-old Brazil international said earlier this month the move, worth about £60m, was "90% certain".
Chelsea have confirmed a £52million fee has been agreed with Shanghai SIPG over the sale of Brazilian midfielder Oscar.
He will become the most expensive signing by a Chinese Super League club, joining up with former Chelsea boss Andre Villas-Boas in January as clubs in the Far East continue to splash the cash.
Oscar has fallen out of favour under Antonio Conte at Stamford Bridge, playing 11 matches this season but has not started in the Premier League for the leaders since mid-September, when Chelsea were beaten 2-1 by Liverpool.
Chelsea said: 'Chelsea Football Club and Shanghai SIPG have agreed terms for the permanent transfer of Oscar.
'We thank Oscar for his wonderful service and wish him the very best of luck for the future.'
Brazil striker Hulk became SIPG's record signing in June, joining from Zenit St Petersburg for £47m on £320,000 a week — but Oscar will leapfrog his countryman as the club's top earner.
The Chinese side confirmed Oscar "will arrive in Shanghai in the coming days to officially join SIPG".
The player, who has won the Premier League, Europa League and League Cup during his four-and-a-half-year spell at Stamford Bridge, will earn a reported £400,000 a week.
Conte last week said the huge money being spent on players by Chinese clubs was a "danger for all teams in the world".
It comes as former Manchester City forward Carlos Tevez is reportedly on the verge of becoming the world's highest-paid footballer by moving from Boca Juniors to Shanghai Shenhua, where he will earn £615,000 a week.