Capped once by England, Jenkinson will be hoping to reignite a stagnant career plagued by injuries, with the 27-year-old having actually played more Premier League matches on loan at West Ham than for Arsenal.
A stress fracture to the lower back first kept Jenkinson out for three months after signing under Arsene Wenger, with torn muscle fibre, knee ligament damage, a dislocated shoulder and an ankle injury all contributing to a failure to hold down a spot in the starting XI.
Jenkinson did play nine matches under Unai Emery last term, but was largely a utility player, operating in several positions including right-back, left-back, centre-back and midfield across a variety of competitions.
The Englishman, who also represented Finland at youth level through his mother's heritage, joins Krystian Bielik, Laurent Koscielny, David Ospina and Takuma Asano in leaving the Emirates across the summer transfer window.
In terms of incomings, the Gunners smashed their transfer record to bring in highly-rated Lille winger Nicolas Pepe and 18-year-old forward Gabriel Martinelli.
Dani Ceballos has also arrived on a season-long loan with Real Madrid, while William Saliba will join up with his new club next season after being loaned back to St-Etienne.
Fans are still hopeful that Arsenal's transfer business is not yet over, with the defensive positions a concern in particular.
Talks are ongoing with Scottish champions Celtic over the payment structure of a £25m ($30.5m) move for left-back Kieran Tierney, with the London side hopeful they can get a deal over the line before the window ends on Thursday.
In addition, the Gunners are keen to sign £70m-rated RB Leipzig centre-back Dayot Upamecano, whom they believe to be a more than capable replacement for former captain Koscielny, who joined Bordeaux in a deal worth €5m (£4.6m/$5.6m).
Arsenal kick off their Premier League campaign on Sunday with a trip to Newcastle and will hope to see more fresh faces in the squad before the first top-flight match of the season.