Undefeated Ukrainian Usyk holds the WBC, WBA and WBO belts while Briton Dubois is the IBF champion.
Usyk has faced Dubois before, earning a controversial ninth-round knockout win in Poland in August 2023 after being given time to recover from what the referee ruled to have been a low blow.
The Ukrainian vacated the IBF belt last year, before a rematch with Britain's Tyson Fury, with Dubois upgraded to champion and defending the title against compatriot Anthony Joshua last September.
"I’m grateful to God for the opportunity to once again fight for the undisputed championship," Usyk said in the statement. "Thank you, Daniel, for taking care of my IBF belt - now I want it back."
Dubois looked forward to taking his revenge.
"I should have won the first fight and was denied by the judgement of the referee, so I will make no mistake this time around in front of my people at the national stadium in my home city," he said.
"I am a superior and more dangerous fighter now and Usyk will find this out for himself on July 19."
The fight, to be broadcast live on DAZN Worldwide and sponsored by Saudi Arabia's Riyadh Season, will be the first time an undisputed heavyweight contest has been held on British soil.
Lennox Lewis was the last British undisputed world heavyweight champion in 1999.