The tombstone, which had the name Trump engraved on it, was found in the Sheep's Meadow area of the park, and was removed overnight.
The tombstone also listed the date 1946, the real estate mogul's birth year, but no year of death was engraved on it.
"Made America Hate Again" was also inscribed on the stone.
It is unclear whether or not the Secret Service considered the tombstone a death threat.
"We're not going to comment on protective procedures or protective knowledge like that," Martin Mulholland, special agent in charge of the Secret Service's office of public affairs, told ABC News today.
A spokesperson for the park told ABC that the tombstone was removed "shortly after it was discovered" on Sunday afternoon.