Only a toddler when Spurs last won a trophy in the 2007-08 EFL Cup, the England youth international was the subject of an accepted £34.9m offer from the North London giants, who left Leeds "heartbroken" by poaching him from the Elland Road ranks.
The Lilywhites - who successfully hijacked Brentford's move for Gray - sent Joe Rodon in the other direction to soften the blow somewhat, and Gray can now proudly claim to have commanded the highest transfer fee for an 18-year-old in British football.
However, the 2006-born phenom is pipped to the all-time post by a handful of Selecao starlets, and here, Sports Mole looks at the most expensive 18-year-olds in football history, using data from Transfermarkt.
10. Estevao Willian (RW | Palmeiras to Chelsea | £28.8m | 2025)
While still 17 years of age, Estevao Willian of Palmeiras - dubbed 'Messinho' - will have turned 18 by the time his £28.8m Chelsea transfer goes through in 2025, and as the transaction has already been confirmed, he nabs 10th place on our list.
The Brazil Under-17 international announced himself to the global stage at the 2023 Under-17 World Cup, where he contributed three goals and three assists during his nation's run to the quarter-finals, before earning his stars domestically.
Estevao had not quite broken into the Palmeiras first team before the 2023 World Cup, but he quickly became a regular starter for the South American giants, who will hold onto him for one more year before he becomes the latest in a long line of teenagers to transfer to the Blues in the Todd Boehly era.
9. Renato Sanches (CM | Benfica to Bayern Munich | £29.6m | 2016)
What could have been for Renato Sanches, whose rise to prominence with Benfica in the 2015-16 season saw him force his way into Portugal's triumphant Euro 2016 squad and earn him a lucrative switch to Bayern Munich.
However, the midfielder failed to live up to his extreme potential in Bavaria and also endured that highly forgettable loan spell with Swansea City, culminating in him leaving for Lille in the summer of 2019.
A renaissance was teased when he helped Les Dogues win the 2020-21 Ligue 1 title, one year before his latest marquee move to Paris Saint-Germain, but he has since reverted to his injury-hit ways and started just one Serie A game during a recent loan spell at Roma.
8. Wayne Rooney (CF | Everton to Manchester United | £31.3m | 2004)
Ask Ronaldinho or Wayne Rooney, and both can recall a time where they lobbed celebrated Arsenal and England goalkeeper David Seaman; the latter's came as a baby-faced 16-year-old for Everton all the way back in 2002.
That memorable first Premier League goal for Rooney preceded his £31.3m switch to Manchester United in 2004 - a record for an 18-year-old at the time - and what followed was the story of the greatest goalscorer the Red Devils have ever seen.
Five-hundred and 59 appearances, 253 goals and 16 major trophies, Rooney's Theatre of Dreams legacy is ever-lasting, although he is yet to reach the same astronomical heights during the embryonic stages of his managerial career.
7. Luke Shaw (LB | Southampton to Manchester United | £31.8m | 2014
Following in Rooney's footsteps as another 18-year-old to join Man United for north of £30m, Luke Shaw shone for the iconic Southampton team of 2013-14 before becoming the most expensive 18-year-old defender in the world.
Shaw has since become a defensive stalwart for the Red Devils over the past decade, but Man United fans need no reminder of his sickening double leg break in 2015, since when fitness issues have continued to bedevil him.
The England international has still racked up over 250 appearances for Man United and remains first choice for club and country when fit, but Gareth Southgate's decision to call him up for Euro 2024 - when he had not played since February - has not been vindicated.
6. Fabio Silva (CF | Porto to Wolverhampton Wanderers | £33.9m | 2020)
One of a plethora of Portuguese players to don the Wolverhampton Wanderers strip since their return to Premier League territory, Fabio Silva was the subject of a £33.9m bid in the summer of 2020 and left Porto to link up with Nuno Espirito Santo's side.
Regular Premier League appearances came Silva's way during his first two seasons at Molineux, but the striker ultimately failed to adapt to the rigours of English top-flight football and has since been loaned out three times.
Anderlecht, PSV Eindhoven and most recently Rangers have all taken Silva on, but he only achieved very moderate success at all three destinations, leaving his long-term future in limbo.
5. Vitor Roque (CF | Athletico Paranaense to Barcelona | £33.9m | 2024)
Speaking of £33.9m 18-year-olds who struggled to settle at their adopted homes, Barcelona new boy Vitor Roque snubbed interest from the Premier League to join La Blaugrana in January 2024 and could hardly have appeared happier at the time.
However, Roque's beaming smile at his unveiling has since turned into a frown of frustration, as he was given just two starts in his first half-season in La Liga, leading to a public warning from his agent that he could leave as quickly as he had arrived if his playing situation did not improve.
The managerial farce surrounding Xavi did not help matters for the Brazilian starlet, but there is optimism that he will play a more prominent role under new boss Hansi Flick.
4. Archie Gray (RB/CM | Leeds United to Tottenham Hotspur | £34.9m | 2024)
Very rarely do teams admit to being "heartbroken" at losing a player in a multi-million pound transfer, but Leeds could not hide their excruciating pain at seeing the much-coveted Archie Gray walk out of the door, knowing that there was nothing they could have done about it.
On account of their failure to get promoted to the 2024-25 Premier League, Leeds were powerless to prevent Tottenham triggering a clause in Gray's contract, and the 2006-born starlet arrived at Hotspur Way mere days after a move to Brentford collapsed.
Earning plenty of plaudits for his displays as both a right-back and central midfielder for the Whites, Gray's versatility makes him perfectly suited to the modern game, and as well as being the most expensive 18-year-old Englishman of all time, he is also the most expensive not to join a particular club.
3. Vinicius Junior (LW | Flamengo to Real Madrid | £38.1m | 2018)
Brazilian wing wizard Vinicius Junior celebrated his 18th birthday by receiving the dream gift for any budding footballer - a Real Madrid shirt - leaving the home comforts of Flamengo behind to join the perennial European champions.
Vinicius's adaptation to life in La Liga did not go as smoothly as some hoped, but the attacker was simply a slow burner and exploded into life in the 2021-22 campaign, which he capped off with the winning goal over Liverpool in the Champions League final.
The South American has continued to go from strength to strength under Carlo Ancelotti, while also using his voice for good off the pitch in the fight against racism, having been subjected to some disgraceful abuse from rival fans during his time in Spain.
2. Rodrygo (RW | Santos to Real Madrid | £38.1m | 2018)
One year after Vinicius swapped the Brasileiro for the Bernabeu, he welcomed another teenage compatriot in Rodrygo to the unforgiving world of Real Madrid, as the latter made the £38.1m switch from Santos.
Like Vinicius, it took a bit of time for Rodrygo to truly come into his own in the Spanish capital - although he was not helped by the COVID-19 pandemic impacting his debut season - but he achieved his first double-figure La Liga campaign for goals in 2023-24.
Rodrygo's 17-goal haul across all tournaments in the 2023-24 season came in spite of the fact that he was mainly deployed in a central role rather than his favoured right-wing position, and with Kylian Mbappe's arrival leading to even more intense competition for attacking spots, Rodrygo's long-term future has been one of the hot-button topics of the summer.
1. Endrick (CF | Palmeiras to Real Madrid | £40.2m | 2024)
Completing the trifecta of silky Selecao stars at the tip of the Real Madrid attack - and at the top of this list - Endrick had just turned 16 years old when he pulled on the Palmeiras strip for the first time, becoming the Brazilian giants' youngest senior player in history.
What followed was a rapid rise to global fame for the 2006-born starlet, who will officially become the most expensive 18-year-old in world football when his £40.2m Real Madrid transfer goes through on July 21 - his 18th birthday.
Also a fully-fledged member of the Brazil national team, Endrick memorably scored his first goal for his country in a 1-0 friendly win over England at Wembley and forced his way into their 2024 Copa America squad, marking a new zenith for a player who had an extremely hard start in life.