The 29-year-old leaves the Premier League side as a free agent, but Bournemouth could earn up to £1.3m in bonuses as well as 20% of any future sale.
Unal had an injury-stricken time at the club, suffering an ACL in his right knee in January 2025, which sidelined him for several months. After returning to action in October 2025.
He then picked up a minor right abductor muscle strain in January 2026.
The forward arrived from Getafe on an initial loan in January 2024 before making the move permanent for about £13m later that year.
"A popular figure within the squad, Unal leaves having made a positive contribution both on and off the pitch during his time with the Cherries," said a Bournemouth statement.
"AFC Bournemouth would like to thank Enes for his efforts during his time with the club and wish him every success for the future."