As previously revealed by Goal, the 34-year-old right-back becomes Unai Emery's first signing as Gunners head coach, having taken over from Arsene Wenger at the end of the 2017-18 campaign.
“Stephan brings huge experience and leadership to our squad," Emery told Arsenal's official website.
"He’s a player with great quality with a very positive and determined attitude. Stephan will improve us on and off the pitch.”
Emery’s first task as Gunners head coach was to strengthen a side which aims to close the gap on their Premier League rivals next season, with defence a clear priority having conceded 51 times in the Premier League during Arsene Wenger's final season in charge.
With Hector Bellerin the only senior right-back at the club Lichtsteiner's arrival is expected to ease the burden on Arsenal's Spain international going into next season, while his leadership qualities are also seen as a key asset.
Ainsley Maitland-Niles is able to deputise at right-back but is viewed as being a more natural defensive midfielder while Carl Jenkinson appears unlikely to break into the starting line-up following a disappointing loan spell at Birmingham City last term.
Switzerland captain Lichtsteiner announced he would be leaving the Bianconeri in early May having helped the club to their seventh successive Serie A title, with the Switzerland international having ended each season since joining the club from Lazio in 2011 as a national champion.
In total he scored 14 goals in 250 appearances for Juventus, though he had fallen down the pecking order in Turin last season. Borussia Dortmund, Monaco and Marseille also showed an interest in signing him.
Lichtsteiner's arrival is expected to be the start of a busy transfer window for Arsenal with Greek international defender Sokratis Papastathopoulos expected to sign for the club in the coming days.