It marks a massive coup for the Gunners who are getting one of the most highly-rated attackers in world football.
Despite going into the summer with a budget of just £40m, they have somehow managed to negotiate a deal to pay the sizeable fee in instalments over the next five years and have beaten off stiff competition to get their man.
Both Manchester United and Liverpool are said to have contacted Lille over a potential move but it is Gunners fans who will be treated to a player with electric pace and a goal threat that was matched by few in Europe last season.
His arrival comes hot on the heels of their capture of talented midfielder Dani Ceballos from Real Madrid on loan and the signing of forward Gabriel Martinelli.
Boss Unai Emery has also moved to bring in centre-back William Saliba but he will continue his development on loan at Saint-Etienne next term.
Emery is expected to bring in some more new faces between now and the close of the window on August 8 with a left-back and a central defender his priority
So, how could they line up at the start of the 2019-20 season? Here, Express Sport takes a look.
Bernd Leno is the undisputed No 1 following Petr Cech’s retirement and Emiliano Martinez is unlikely to push him for a starting spot.
In defence, Hector Bellerin is nearing a return to fitness and while he might not be ready for the opening game of the season the Spaniard will slot straight back as first-choice right-back as soon as he is fully fit.
Sokratis Papastathopoulos is certain to keep his place at the heart of defence but he will probably need a new partner.
Laurent Koscielny has been told he will play no part in the first team after going on strike in pre-season in a bid to force a move to France and Shkodran Mustafi is out of favour and reportedly closing in on a switch to Monaco.
Arsenal have been heavily linked with a loan move for Juventus star Daniele Rugani and it is beginning to make sense for all involved.
Juve will not want to sell one of the most highly-rated defenders in Italy and Arsenal could not afford a permanent deal.
His chances in Italy will be limited next season with the arrival of Matthijs de Ligt and so he looks like the ideal partner for Sokratis.
Left-back is another problem position for the Gunners with 33-year-old Nacho Montreal entering the twilight of his career, while Sead Kolasinac is far better suited to a wing-back role when Emery opts for five at the back.
Reports claim the club are close to agreeing a deal with Celtic for Kieran Tierney and if they get a deal over the line the Scot can expect to slot straight into the starting XI.
Ceballos should also come straight into the side in the centre of midfield and will probably play alongside Granit Xhaka with Mesut Ozil in front of them.
Matteo Guendouzi will push Ceballos and Xhaka for a starting spot but might have to make do with more minute from the bench.
That leaves Nicolas Pepe on the right of a formidable-looking three-man attack that also includes, Alexandre Lacazette and Pierre-Emerick Aubameyang.
How Arsenal could line up next season: Leno; Bellerin, Sokratis, Rugani, Tierney; Ceballos, Xhaka, Ozil, Pepe, Lacazette, Aubameyang.

https://www.express.co.uk/sport/football/1160008/Arsenal-line-up-Nicolas-Pepe-transfer-news

where is torreira? We all know both ceballos and xhaka are not good tacklers

bolakale97:
where is torreira? We all know both ceballos and xhaka are not good tacklers

Guy! It's an assumption

Me i even prefer that torreira or Guendouzi than that rubbish xhaka

Arsenal will still get trashed by city and finish in the europa league places this season.

smoke9910:
Arsenal will still get trashed by city and finish in the europa league places this season.

E get who dem no trash last season? Why? Arsenal own dey pain you like this na?

so Ceballos is even a CMF, I thought he was an attacker