Joshua, who will is aiming to take back his heavyweight titles after unexpectedly losing his first professional fight to Ruiz in NY at Madison Square Garden on 1 June, welcomed the announcement on social media with the message: "Neutral grounds - LETS GO".
Recently, Saudi Arabia hosted Callum Smith vs George Groves, and Amir Khan vs Billy Dib.
Returning to the scene of the crime at Madison Square Garden was considered but talks ceased with the NY venue last month. It also hosted the World Boxing Super Series super middleweight final between British fighters Callum Smith and George Groves past year.
Of course, the first meeting between Joshua and Ruiz Jr. saw the Mexican spring the upset in stunning fashion - stopping the Englishman for his first career defeat in a fight, that by all accounts, he should have been winning comfortably.
In the seventh, Ruiz Jr dropped Joshua twice more, and the referee chose to stop the fight.
Amnesty International criticised the choice of Saudi Arabia for the bout, citing human rights violations, the murder of journalist Jamal Khashoggi, and the ongoing war in Yemen.
Joshua and his promoter Eddie Hearn immediately activated their rematch clause and targeted a bout in the United Kingdom but Ruiz Jr responded: "That is not going to happen".
"Despite some long-overdue reforms on women's rights, Saudi Arabia is now in the grip of a sweeping human rights crackdown - with women's rights activists, lawyers and members of the Shia minority community all being targeted". Either way, Ruiz is now the rightful heavyweight champ and Joshua is looking avenge himself.