Inter confirmed the signing of Dumfries shortly after revealing striker Edin Dzeko had completed his switch from domestic rivals Roma.
Dumfries, who was impressive for the Netherlands at Euro 2020, scoring twice during the tournament, is believed to have been purchased for a fee of €12.5million plus add ons.
The 25-year-old has signed a four-year deal with the Nerazzurri.
Dumfries appears set to be the like-for-like replacement for Achraf Hakimi, who was sold to Paris Saint-Germain earlier in the transfer window.
Hakimi's sale was required as Inter looked to ease financial difficulties. The club have also seen star striker Romelu Lukaku depart to Chelsea for a reported £97.5m (€115m).
"The feeling is amazing," Dumfries told Inter TV. "I'm very happy to join the champions of Italy. It's a big opportunity for me and I'm happy to be here.
"I'm a wide defender and I like to attack a lot. I think I'll fit in at Inter as they play with five at the back, as I have done with the Netherlands.
"I know which Dutch players have played here before. It's an honour to join them on the list.
"I hope we can have a great season, maybe win another league title and do well in the Champions League. I can't wait to get started."
Dumfries excelled for Frank de Boer's Netherlands team at Euro 2020, despite the Oranje's disappointing exit to the Czech Republic in the round of 16.
Playing as a wing-back, Dumfries started all four of his country's matches, playing 315 minutes in total.
Inter look set to continue with a back three under new boss Simone Inzaghi, who used a similar system at Lazio, meaning Dumfries will likely slot straight into the role that Hakimi occupied last term.
Dumfries has big shoes to fill, though. Hakimi played in 37 league matches in 2020-21, with only Lautaro Martinez (38) featuring more in the top flight under Antonio Conte during the campaign.
Hakimi scored seven times, a total only bettered in Inter's ranks by Martinez (17) and Lukaku (24), while he also provided eight assists.
His crossing was a particular threat, registering an accuracy of 25.52 per cent from 145 crosses from open play. Based on Euro 2020, this is something that Dumfries will need to improve, given none of his six crosses were classed as successful.
However, his presence in the area was often enough to help the Netherlands break down defences, and only Memphis Depay (24) had more touches in the opposition box than Dumfries.
Dumfries also contested (58) and won (28) more duels than any other Dutch player at Euro 2020, recording a success rate of 48.28 per cent, a figure that is not dissimilar to Hakimi's rate of 50.05 per cent from 333 duels in Serie A last season.
Caicedo, 21, has been one of the breakout stars of the Premier League season, starting 18 of Brighton's 19 league fixtures to help his side up to sixth.
The talented central midfielder has already earned 28 caps for Ecuador and collected valuable experience at the Qatar World Cup, where he scored against Senegal in the group stage.
Brighton have rejected some serious bids already this month, and while they have reportedly set Caicedo's price at nine figures, Arsenal are prepared to test how much money they are willing to turn down.
TOP STORY – ARSENAL PREPARE BUMPER BID FOR BRIGHTON TALENT
According to Fichajes, Arsenal are determined to add reinforcements before the end of January, and they will see if £75m is enough to pry Caicedo away from Brighton.
Metro had previously reported Brighton would hold out for a fee in the range of £100m, having already batted away a £50m approach from Chelsea.
Fichajes believes Arsenal are willing to outspend Chelsea in the pursuit of Caicedo, which has them in the driver's seat if Brighton are willing to budge before the transfer window closes.
ROUND-UP
– According to the Daily Telegraph, Chelseaand Liverpoolwill both pursue 24-year-old Wolves midfielder Matheus Nunes, who is expected to cost £55m.
– 90min is reporting Tottenhamare confident they will complete their move for 23-year-old Sporting right-back Pedro Porro in the coming days after negotiations over his release clause.
– 90min adds Sportingwill target 22-year-old Brighton full-back Tariq Lamptey as Porro's replacement, although Lyonare also interested in the Seagulls defender.
– Everton have lowered their asking price for Anthony Gordon to £40m plus add-ons after their initial £60m valuation put off Newcastle United, per the Telegraph.
– Gazzetta dello Sport is reporting Inter will demand £35m (€40m) for 26-year-old right-back Denzel Dumfries, who is a target of Chelsea, Newcastleand Manchester United.
Los Blancos, along with Paris Saint-Germain, Chelsea, Manchester United, Barcelona and Bayern Munich, were keen on the former Borussia Dortmund forward.
Ultimately, the Norwegian decided to join Manchester City, starting on fire with 14 goals in 10 games in all competitions, but Madrid are keeping an eye on him.
TOP STORY – MADRID PLANNING LONG-TERM MOVES FOR CITY DUO
Spanish giants Real Madrid are plotting moves to sign Manchester City pair Joao Cancelo and Erling Haaland, reports AS.
Madrid will attempt to sign the 28-year-old Portuguese full-back in mid-2023, with Cancelo contracted until 2027, although the report claims he will cost around €40-50million (£35-44m).
The Spanish champions are planning a swoop for Haaland but not until 2024, with Karim Benzema in the twilight of his career.
Haaland reportedly has a termination clause in his City contract worth €180m (£158m) up until 2024.
ROUND-UP
– The Daily Star reports that Manchester United and David De Gea are set for key talks on his future, with the goalkeeper's contract expiring in mid-2023. United hold an option to extend his stay.
– Manchester United may struggle in their bid to sign Aston Villa goalkeeper Emiliano Martinez, with the Villans to turn down any offer for him in January, claims Football Insider.
– Barcelona are keen to sign Wolves 25-year-old midfielder Ruben Neves as a long-term replacement for 34-year-old Sergio Busquets, reports Sport. Neves will be the Blaugrana's top target at the end of this season.
– Gerard Pique is not interested in joining Atletico Madrid in January, claims Sport. The defender has fallen out of favour at Barcelona, but he is determined to fight for his spot.
– Calciomercato claims that Chelsea are interested in Inter wing-back Denzel Dumfries. The Italian club may be willing to part with the Dutchman for approximately £44m.
– Colombian forward Luis Muriel is ready to leave Atalanta, with a move to Fiorentina on the cards, according to Calciomercato.
– PSV striker Cody Gakpo is likely to have more offers in January with Manchester United, Southampton and Everton all still interested, claims Football Transfers.
– Thomas Tuchel is Real Madrid 's preferred replacement for Carlo Ancelotti, according to El Nacional. The Italian has told the club he does not intend to manage Madrid beyond this season.
