Tottenham have agreed a four-year deal worth £34million for internet casino group Mansion to be the club's shirt sponsor.
The deal, which becomes effective on July 1 when Spurs' deal with Thomson holiday company runs out, is understood to be among the top 10 largest shirt sponsorship agreements in the world.
Spurs have also changed their shirt manufacturer for next season, with Puma taking over from Kappa, and South Korean company LG Electronics were originally linked with becoming the club's fourth shirt sponsor.
Mansion were in line to sponsor Manchester United until the deal fell through last month.
Spurs chairman Daniel Levy said: 'Tottenham has made progress both on and off the pitch in recent years which has put the club in a good position to improve its commercial partnerships and the new agreement marks a significant uplift.'
Martin Jol's side just missed out on a place in the Champions League this season but their fifth-placed finish in the Premiership means they will play UEFA Cup football next term.
'Spurs have enjoyed an excellent season with European football to look forward to next year,' said David Kinsman, Mansion chief operating officer.