The 31-year-old leaves French side Paris SG for Saudi football team al-Hilal.
This is confirmed by the Saudi club on social media.
The transition sum is said to be around one billion kroner.
In al-Hilal, Neymar becomes a clubmate with other star signings such as Kalidou Koulibaly (Senegal), Rúben Neves (Portugal) and Malcom (Brazil).
Saudi Arabia has invested heavily in football during the summer. In the past, big names like Cristiano Ronaldo and Karim Benzema have chosen to play in the domestic league.
The move has been accused of sports laundering – an attempt to clean up the kingdom’s poor human rights record.