Stones, 32, has signed on a free transfer after leaving Manchester City at the end of June following ten trophy-laden seasons at the Etihad.
The defender put pen to paper on a two-year deal with the Nerazzurri, running until the summer of 2028, and told the club's channels: "I'm someone who is very hungry to win again. I've been very, very lucky and fortunate to have won so many things in the past.
"I want to bring that experience here and help the team, help the club and keep learning and growing as a player."
The move brings Stones a haul of silverware from his time under Pep Guardiola: six Premier League titles, one Champions League and three FA Cups, along with a series of domestic and international trophies, and a regular place for England at last month's World Cup, where the Three Lions finished third. Despite injury problems in recent seasons, the centre-back remains regarded as one of the most technically refined defenders of his generation, a profile that fits neatly with Cristian Chivu's footballing ideas at Inter.
Reports in Italy put the deal at around €4m a season, terms said to be considerably lighter than those demanded by some of the other defensive targets Inter had considered this summer, including Tottenham's Cristian Romero.
His arrival also reunites him with Manuel Akanji, who joined Inter from City last year before making the move permanent this summer, and who has since established himself as a key figure in Chivu's defensive setup; the pair won seven trophies together during three years as central defensive partners at City. Stones came through the youth ranks at Barnsley before a spell at Everton preceded his 2016 move to City, where he went on to make 295 appearances and score 19 goals across a decade at the club.
There is a curious footnote linking Stones to his new club, and in particular to his new central-defensive partner Alessandro Bastoni.
In the 2023 Champions League final in Istanbul, won 1-0 by City, the pair clashed during a heated exchange in the first half. Television cameras caught Stones mouthing an unusual jibe at the Inter defender during a corner-kick scuffle: "You need to brush your teeth."
The moment went viral among fans at the time and takes on a rather different flavour now, with the two men going from rivals on the biggest stage in Europe to teammates aiming to bring Inter back to the top of the continental game.