According to The Athletic, Roberto De Zerbi’s side have reached an agreement with London rivals over a permanent move for the 28-year-old.
It’s understood that the centre-back has already agreed to personal terms, and he has been granted permission to undergo a medical.
Adarabioyo now looks set to become Tottenham’s ninth signing of the summer and could be followed by Mykhailo Mudryk.
A loan deal has been agreed for the Ukrainian but personal terms still need to be finalised with the forward.
The defender’s transfer from Stamford Bridge to Tottenham marks the first time a player has moved between the two clubs since Carlo Cudicini in 2009.
Adarabioyo made 16 Premier League appearances for Chelsea last season, just eight of them were from the first whistle, however.
The deal comes after Kevin Danso informed Tottenham that he would like to leave the club with a move to Sunderland said to be close for the Austrian.