Grand Slam Tennis is family owned and operated business, Celebrating over 40 years in business. Jim Donnelly has been a proud owner and operator of Tennis Emporium & Grand Slam Tennis for over 42 years. Grand Slam Tennis was opened in the year 1986, after the birth of Jims youngest son Chase, who is currently his business partner. An owner can always be found in either location. Chase operates the Commack Store and Jim operates Miller Place. We are proud to be a customer friendly Tennis store and have recently expanded our brand and have opened a 2nd location in Miller Place.