Mikel Arteta is set to splash over £200m on new signings this summer with Declan Rice set to join Timber and Kai Havertz in arriving at the Emirates Stadium.
The Gunners completed the agreement for Timber earlier this week but only today unveiled the defender as an Arsenal player due to a hold-up around his contract.
Arteta said : “We’re really excited that Jurrien has joined us. He is a versatile young defender, who will fit into our system and provide our squad with so much added quality.
“Jurrien is a young player, but has already achieved so much. He has experienced what it’s like to go to a major international tournament on more than one occasion, as well as the trophies he has won with Ajax. We look forward to welcoming and integrating Jurrien into the squad.”
Versatile defender Timber can operate on the right side of defence or in the middle and was a target for Manchester United last summer before opting to stay one more year in Amsterdam.
Timber has signed a five-year deal at the Emirates Stadium after undergoing a medical. He’ll wear the No12 shirt.
Arsenal will pay an initial £34m for the Netherlands international with £4m in add-ons as part of the deal.
Sporting director Edu said: “We are very happy to bring Jurrien to Arsenal. He is a player that we have admired for a long time, so it’s a credit to everyone in our team that made this happen.
“Jurrien is a young talented international player, who fits our vision of competing with a young strong squad. I know Jurrien cannot wait to get started and we’re really hoping that he will be a great success here for many years.”