Depay's performances in recent weeks have caught Van Gaal's eye and the 19-year-old was named for the World Cup qualifiers against Hungary and Turkey despite failing to make the provisional party.
Nigel de Jong and Gregory van der Wiel were also called up after lengthy absences from the international scene.
AC Milan midfielder De Jong has not played for Oranje since November 2012, due largely to a serious Achilles injury, while Paris St Germain full-back Van der Wiel was awarded his first call-up under Van Gaal.
Holland have already qualified for the World Cup finals in Brazil next summer but it remains to be seen whether Hungary, Turkey or Romania finish second in Group D.
Van Gaal's men host Hungary in Amsterdam next Friday before visiting Turkey four days later.
Holland squad: Jasper Cillessen (Ajax), Tim Krul (Newcastle), Michel Vorm (Swansea); Daley Blind (Ajax), Jeffrey Bruma (PSV), Daryl Janmaat (Feyenoord), Bruno Martins Indi (Feyenoord), Ron Vlaar (Aston Villa), Stefan de Vrij (Feyenoord), Gregory van der Wiel (Paris St Germain), Jetro Willems (PSV); Jordy Clasie (Feyenoord), Jonathan de Guzman (Swansea), Nigel de Jong (AC Milan), Stijn Schaars (PSV), Wesley Sneijder (Galatasaray), Kevin Strootman (PSV), Rafael van der Vaart (Hamburg); Memphis Depay (PSV), Dirk Kuyt (Fenerbahce), Jeremain Lens (Dynamo Kiev), Robin van Persie (Man Utd), Arjen Robben (Bayern Munich).