The beaten 2017/18 A-League grand finalists will meet Madrid-based CD Leganes along with two other clubs, whose identity is yet to be determined.
Jets CEO Lawrie McKinna set up the opportunity after spending a handful of days in Madrid in March, via links with the Genova International School of Soccer (GISS) where he met with the Leganes owner. 
"We're getting that signed off, hopefully tonight or tomorrow night," McKinna told FourFourTwo.
"We're definitely playing against Leganes and the other two games, we've been given a list of teams, and we need to decide."
GISS also have strong links with Getafe, who finished seventh in La Liga in 2017-18, as well as Deportivo Coruna who just suffered relegation from the top flight.
Melbourne City and Sydney FC have previously played pre-season matches in Europe but not against the level of opposition which the Jets have lined up.
City played several English lower league clubs at the City Football Group's Manchester Training Camp in 2014, while Sydney played six games in Italy during Alessandro Del Piero's time at the club in 2013.
McKinna added: "The Genova International School of Soccer will be sponsoring it and covering the costs of the trip. They work with Leganes who are putting it together."
The Jets will also venture to southern China in early June during a blockbuster pre-season.
Newcastle, along with Sydney FC, will compete in the 2018 Free Trade Port Super Champions Cup, where they'll face Chinese Super League clubs Beijing Guoan and Shanghai Shenhua in Haikou.