Villarreal are yet to confirm the venue for the 7pm kick-off but away supporters will not be allowed. The game will be streamed live on LIVENow.
It will be Leeds's final match before travelling to Manchester United for the start of the new Premier League season seven days later. The Red Devils' preparations have been disrupted by Covid-19 infections which caused them to cancel their July 31 friendly against Preston North End.
The game against Villarreal, who beat Ole Gunnar Solskjaer's side on penalties to win the Europa League in May, follows a game against Ajax in Amsterdam on August 4. Coronavirus restrictions mean no away fans will be allowed in the Johan Cruyff Arena.