Former Ajax man Sanchez bids farewell to North London following six years of service for Tottenham, during which time he came up with five goals and one assist in 207 matches.
Sanchez was only a fringe player during Antonio Conte's reign, though, as Eric Dier, Cristian Romero, Ben Davies and Barcelona loanee Clement Lenglet were preferred in defence.
The Colombia international still managed 24 appearances in a Spurs shirt last season, but he was booed by his own supporters during a horror cameo in a 3-2 home loss to Bournemouth under Cristian Stellini.
With Sanchez's Spurs deal due to expire in the summer of 2024, an exit was seen as inevitable, especially with Micky van de Ven and Ashley Phillips arriving to bolster the backline.
Spartak Moscow and Rennes both came forward with offers for Sanchez, but the defender was reluctant to move to Russia, while Rennes' late bid worth £7.7m was rejected.
However, the 27-year-old has now ended his association with the Lilywhites to join Galatasaray, who have tied him down to a four-year contract with an option to extend until 2028.
The Turkish giants have confirmed that they will pay £8.1m to Tottenham for the centre-back, who will collect £2.7m in yearly wages during his time in Turkey.
Sanchez made two appearances for Spurs in the 2023-24 season, coming off the bench in their Premier League opener against Brentford before missing a penalty as the Lilywhites crashed out to Fulham in the third round of the EFL Cup.
Only a few moments after Sanchez's transfer was announced, Spurs also confirmed that Galatasaray had signed midfield outcast Ndombele on a season-long loan with an option to buy for £12.8m.
The former Lyon man's record-breaking move to the Tottenham Hotspur Stadium has not worked out for club or player, as he has failed to justify his £53m price tag over the past four years.
Ndombele has come up with 10 goals and nine assist in 91 matches for Spurs since joining in 2019, but he has also been loaned back out to former club Lyon and Napoli over the past couple of years.
While on the books in Italy, the 26-year-old scored twice in 40 games for Napoli and made 30 Serie A appearances during their run to the title, although he only started eight of those contests.
Spurs have desperately been trying to offload Ndombele over the summer, but should Galatasaray not take up their option to sign him permanently, he will return to Tottenham ahead of his contract expiry in 2025.
Sanchez and Ndombele's exits takes Tottenham's summer departures up to nine, as the pair follow Harry Kane, Harry Winks, Lucas Moura, Djed Spence, Joe Rodon, Japhet Tanganga and Sergio Reguilon out of the club.
The Lilywhites are also hoping to find a buyer for exiled goalkeeper Hugo Lloris, who is already said to have rejected contract offers from Nice and Newcastle United, but clubs in Saudi Arabia could try to sign the Frenchman before their transfer window shuts on Thursday.