The centre-back, who will become a free agent when his contract at Craven Cottage expires on June 30th, has agreed a long-term deal with the Blues ahead of a free transfer.
He came through the academy at Manchester City, where he worked under prospective Blues boss Enzo Maresca, who used to be the club’s Under-21 coach.
While Chelsea are poised to announce Maresca as their new boss, they are also in the final stages of clinching a deal to reunite the coach with Adarabioyo.
It will be a huge blow to Newcastle, who have regarded the 26-year-old as a top target.
talkSPORT understands the Magpies have been pushing for an answer from Adarabioyo, who also had interest from Manchester United, having first made contact over a move weeks ago.
The Tyneside outfit were believed to be confident of pulling off a double deal this summer for the defender, as well as Bournemouth star Lloyd Kelly.
talkSPORT understands Adarabioyo was waiting to see who qualified for European football, with Chelsea sealing a place in the Europa Conference League, while Newcastle were left empty-handed.
The Blues consider the Englishman to be a proven Premier League player and were drawn to him for aerial prowess, along with a strong injury record and his previous experience working with Maresca.
Adarabioyo would join a Chelsea side that has City’s fingerprints all over it, with Cole Palmer and Romeo Lavia also coming up through the champions’ academy.
Director of football Joe Shields also used to be the chief scout at the Etihad and has had plenty of say in the transfer window under Clearlake Capital’s ownership of the Blues.
Chelsea are expected to sell academy stars this summer, including Trevoh Chalobah, who has interest from United and Bayern Munich.
They are also looking to replace Thiago Silva after the veteran defender announced his exit earlier in the season.
Signing free agent Adarabioyo will also be a boost to Chelsea’s efforts to keep in line with the Premier League’s profit and sustainability rules, having spent lavishly in the last two years.
The Fulham star has been a key player under Marco Silva, though he missed the start of the season due to groin surgery.
This season, he made 25 appearances in all competitions and a total of 132 for the Cottagers.
