The former FC Porto star was confirmed as an Arsenal player on Tuesday after the completion of a £34 million deal with Porto.
The deal includes an initial fee of €35m (£30m) in addition to €5m (£4.3m) worth of add-ons.
In all, Vieira is Arsenal’s third new signing of the summer after bringing in goalkeeper Matt Turner and teenage winger Marquinhos.
“I am very excited that we have identified and signed such a special talent. Fabio is a very creative player that will bring high quality and versatility to our attacking play” said Mikel Arteta.
“We welcome Fabio and his family to our club and are looking forward to starting work with him ahead of the new season.”
The Gunners are still in the transfer market for a few more signings before the start of the 2022/23 campaign in August.