Reguilon is off to the English capital on a five-year deal for a reported €30-million transfer fee. The agreement between the two parties includes a buyback option for Real and the chance to match any future bids for the 23-year-old, according to The Guardian's Fabrizio Romano.
A product of Real's famed youth setup, Reguilon enjoyed a breakthrough loan spell at Europa League winners Sevilla last season after failing to crack Zinedine Zidane's first team.
In addition to Reguilon, Jose Mourinho's team is expected to finalize a move for fellow Real Madrid outcast Gareth Bale; the 31-year-old Welsh winger is on the verge of returning to his former club.
Manchester United, who have also been linked with Bale, were reportedly interested in Reguilon's services, eventually declining to make a formal bid because of Real's insistence on including a buyback clause in negotiations.