As reported by the Irish Examiner a fortnight ago, the Blessington native has joined the Viola after a wait for international clearance during which she was training with the club.
The centre-back, who has earned 79 caps, joins a club that was second behind Juventus when the season was curtailed due to Covid-19. Backed by their new owner, billionaire Rocco Commisso, they will enter next season’s Champions League at the last-32 stage.
It comes after her surprise release from Arsenal, ending a three-year spell with the club.
She was an integral part of their league-winning side of 2018/19 but struggled for game-time in their title defence, although she did feature against her new club in the Champions League last-16 win last September.
Quinn had previously spent stints at Eskilstuna United in Sweden and English club Notts County after learning her trade on the domestic scene with Peamount United.