All Tennis Players How Many Grand Slams Has Ivan Lendl Won? Ivan Lendl (Czech pronunciation: [ˈɪvan ˈlɛndl̩]; born March 7, 1960) is a former professional tennis player.Ivan Lendl has won 8 Grand Slams. FacebookTwitterEmail How Many Grand Slams Has Madison Keys Won? How Many Grand Slams Has Jannik Sinner Won? How Many Majors Has John Isner Won?