This follows the £32 million signing of Oleksandr Zinchenko from Manchester City.
The Gunners have now spent £121.5 million on new players ahead of the new season, according to Sky Sport..
They are followed by Tottenham Hotspur (£115 million), Manchester City (£101.1 million), Leeds United (£95.4 million), Liverpool (£91.5 million) and Chelsea (£81.5 million).
Arsenal could be toppled by London rivals, Chelsea, who are set to seal a deal for Sevilla defender Jules Kounde.
The Blues have reportedly struck a £55 million fee for Kounde and have offered the player a five-year contract.