Kammala jumla mai zuwa: Tare da buga wasanni 167 na kasa da kasa, Casillas yana da na biyu mafi yawan wasanni ga tawagar kasar Spain, yana mai da shi dan wasan kwallon kafa na goma mafi yawan 'yan wasa a kowane lokaci. Wanda ba a yi amfani da shi ba a UEFA Euro 2000, Casillas ya zama mai tsaron gida na farko a gasar cin kofin duniya ta 2002, kuma ya ci gaba da taka leda a
UEFA Euro 2004 da kuma gasar cin kofin duniya ta 2006. A shekara ta 2008, an sanya shi kyaftin, kuma ya jagoranci tawagar zuwa gasar zakarun Turai a wannan shekarar. Casillas kuma ya jagoranci Spain zuwa gasar cin kofin duniya ta farko a 2010, inda ya ci gaba da rikodin rikodi biyar, ya lashe kyautar Yashin ga mafi kyawun mai tsaron gida na gasar. Spain ta zama ƙasa ta farko da ta riƙe Gasar Turai, ta sake lashe taken a 2012, inda ya kafa tarihi don mafi yawan mintuna a jere ba tare da cin kwallo a gasar ba (509). A cikin 2014, Casillas ya zama ɗaya daga cikin 'yan wasa huɗu don wakiltar Spain a gasar cin kofin duniya huɗu.