Just before the announcement, the centre-back posted on Twitter: "Swansea medical complete," with reports suggesting that the Swans will pay in the region of £1 million after he was unable to mount a challenge for a place at the Emirates Stadium.
|THE GOAL LINE
|7/5||Arsenal are 7/5 with PaddyPower to finish outside the Premier League top four
The move may come as a surprise to some, with the former England Under-17 international expected to challenge for a first-team berth at the Gunners this season after being listed as part of the main Arsenal squad and being handed the No.35 shirt for the 2012-13 season.
The Stockport-born defender had been at the club since the age of 16 and was also part of Arsenal's touring squad to Asia in the summer, playing in matches against a Malaysia XI, Manchester City and Kitchee.
Bartley, who can also play in defensive midfield, had previously captained the Gunners' reserves, won the FA Youth Cup in 2009 and had also played in Europe on one occasion for Arsene Wenger's side.