Germany goalkeeper Bernd Leno has agreed to join Arsenal from Bayer Leverkusen for a reported 22m euros (£19.3m).
Leno, 26, has made more than 230 appearances for the Bundesliga side.
He has won six caps for Germany but was not included in their World Cup squad.
“Happy and proud to play for this great club Arsenal in the future! I’ll do my best and I’m looking forward to the start of the new season as a Gunner,” Leno tweeted.
Arsenal said the deal is “subject to the completion of regulatory processes”.
“Bernd is a goalkeeper of high quality and experience,” Arsenal manager Unai Emery said.
“He has been a top performer and regular number one goalkeeper for the past seven years.”
A Leverkusen statement said Leno had signed a “long-term contract” with Arsenal.
Petr Cech and David Ospina are Arsenal’s current first-team goalkeepers.
New manager Emery signed defender Stephan Lichtsteiner on a free transfer from Italian champions Juventus this month.