0425 GMT July 19, 2019
The 28-year-old forward joins the north Londoners on a "long-term contract" after four seasons at Dortmund, the club confirmed, The Independent reported.
Arsenal has been in negotiations with Dortmund over the signing of Aubameyang for a number of weeks but a breakthrough was finally made over the weekend.
Dortmund had initially wanted £61 million (€70 million) and turned down Arsenal’s opening offers of £40 million and £44 million for the Gabon international. The north Londoners later raised their offer to £56 million, plus add-ons, which Dortmund agreed to.
Dortmund’s willingness to sell Aubameyang, the 2015 African Footballer of the Year, stems from a break down in relations between the player and the club. The 28-year-old was twice dropped by the Germans this season due to disciplinary reasons, with Dortmund officials keen to move the forward on.
Despite this, Dortmund's sporting director Michael Zorc thanked Aubameyang for his four years of service at the club.
"Apart from the unpleasant events of recent weeks, we like to remember that the story of Pierre-Emerick Aubameyang at BVB for more than four years was a single success story," he said.
"He has done great things for Borussia Dortmund at this time, scored many important goals and is part of the team that brought the DFB Cup to Dortmund in 2017. We wish Pierre-Emerick all the best for his future at Arsenal. "
The Gabonese is Arsenal’s second signing of the January transfer window, following Henrikh Mkhitaryan who joined last week from Manchester United in a player-swap with Alexis Sanchez.
Mesut Ozil committed his future to Arsenal by signing a new three-and-a-half year deal, according to the BBC.
The German international’s deal at the London club was set to expire at the end of the season but the 29-year-old has put pen to paper on a deal thought to be worth £350-per-week before tax.
Ozil had been linked with a summer switch to Manchester United but the former Real Madrid man has committed to the club until the summer of 2021.