The 19-year-old Croatia international has agreed a five-year contract at Falmer Stadium, with the option of a further 12 months, and arrives on the south coast without ever having made a competitive appearance for Spurs.
Vuskovic spent last season on loan at Hamburg, where six goals in 30 games earned him the Bundesliga's Rookie of the Season award and a place in the division's Team of the Year. He carried that momentum into the World Cup, making his debut for Croatia in the group-stage meeting with England last month.
The centre-back fills the hole left by Jan Paul van Hecke, who moved in the opposite direction to Tottenham in a £52m deal, and manager Fabian Hurzeler has urged patience while the teenager settles in.
"Luka has enjoyed a fantastic start to his career - it's one we've followed closely.
"Last season he demonstrated he can play at a very high level and we want to help him build on that within our environment.
"There's been a lot of external noise about Luka joining us, but he is still a young guy who will need time to adjust to the demands of playing for Brighton and the Premier League. We are confident that he will take this in his stride though."
Vuskovic's rise has been rapid. A product of the Hajduk Split academy, he made his senior league bow in February 2023, just two days after turning 16, becoming the joint-youngest player ever to appear in Croatia's top flight. Loan spells followed at Radomiak Radom in Poland and Westerlo in Belgium before his move to Tottenham, where competition from Cristian Romero, Micky van de Ven and Kevin Danso limited his pathway to the first team.
Sky Sports reports that Tottenham have protected themselves in the deal, negotiating a 20 per cent sell-on clause and matching rights that could allow them to bring the defender back to north London in the future. The fee could also rise to £50m through performance-related add-ons.
Only Harry Kane, Gareth Bale and Kyle Walker have left Spurs for bigger fees, while for Brighton the outlay comfortably eclipses their previous record as they back Hurzeler with a statement of intent for the new campaign.