The Black Cats had already confirmed a game against Sporting CP as part of their stay on the Algarve.
And Regis Le Bris’ side will now take on Sevilla, who finished 16th in La Liga last season, at the Estadio Algarve on Saturday, July 19, two days before they face Sporting.
The two games will both be staged at the same stadium in southern Portugal, and will both kick-off at 8pm.
Ticketing information for the games will be released in due course, although Sunderland are advertising package trips to attend both matches on their official website.
