The Chile superstar, who cut short his holiday to finalise the transfer in London, completed a medical and agreed a four-year contract – with the option of a further 12 months – worth up to £140,000-per-week.
The package will put him on a par with current top earner Mesut Ozil.
“I’m so happy to be joining Arsenal, a club which has a great manager, a fantastic squad of players, huge support around the world and a great stadium in London,” said the 25-year-old.
“I’m looking forward to meeting my new team-mates and to be playing for Arsenal in the Premier League and Champions League.I will give my best to Arsenal and want to make all the supporters happy.”
The deal paves the way for Liverpool’s Luis Suarez to replace him at the Nou Camp, with a sum of £75m touted for the Uruguayan striker.
-Daily Mail and AFP
Ever since Arsene Wenger discovered Sanchez was available, the Chile international has been his No 1 summer transfer target.
And Wenger was purring after his first signing of the summer, adding: “As many people have seen during the World Cup this summer, Alexis is a fantastic footballer and we are delighted that he is joining us at Arsenal.”
“As many people have seen during the World Cup this summer, Alexis is a fantastic footballer and we are delighted that he is joining us at Arsenal Football Club,” said Wenger.
“Alexis will add power, creativity and much quality to our squad and we are all looking forward to him joining up with us in a few weeks.
“He has consistently produced top-quality performances at the highest level for a number of seasons now and we are all excited to see him integrate into the Arsenal squad.
“I’m sure all Arsenal supporters will join me in welcoming Alexis to our club.”
Sanchez played a prominent role in Chile’s progression to the last 16 of the World Cup, scoring twice in four matches, before his country bowed out to host nation Brazil in a penalty shootout.
The Chilean is Arsenal’s first signing of the summer with the Gunners also reportedly close to tying up a deal to sign France right-back Mathieu Debuchy from Newcastle United.
They have also been linked with a move for Debuchy’s compatriot Loic Remy, who scored 14 goals on loan at Newcastle from parent club QPR last season.