The event at the Indianapolis Motor Speedway, where average lap speeds exceed 230mph, is traditionally held on the last Sunday in May.
It is the latest major motorsport event to be affected by coronavirus.
The first eight Formula 1 races have been called off and the Le Mans 24 Hours delayed until September.
The Indy 500 is the biggest race on the US motorsport calendar, and attracts around 300,000 spectators. This year, interest will be increased by the presence of two-time F1 champion Fernando Alonso.
The 38-year-old Spaniard is making his third attempt at the event, and if he wins would become only the second man in history to win motorsport’s ‘triple crown’ of Monaco Grand Prix, Le Mans and Indy 500.
Indianapolis owner Roger Penske, a legendary figure in US motorsport for the success of his Indycar teams over the last 50 years, said: “The month of May at the Indianapolis Motor Speedway is my favourite time of year, and like our fans, I am disappointed that we have had to reschedule the Indianapolis 500.
“However, the health and safety of our event participants and spectators is our top priority, and we believe that postponing the event is the responsible decision with the conditions and restrictions we are facing.”
The Indy 500 runs over more than a week, with a series of practice sessions leading up to a two-day qualifying period that takes place the weekend before the race.
The plan for the rescheduled event is to have practice on 12-14 August, followed by qualifying on 15-16 August.