The report quotes Gen Amir Ali Hajizadeh, chief of the Guard's aerospace division, as saying the missile destroyed a target from a distance of 250 kilometers (155 miles). It said the sea-launched ballistic missile dubbed Hormuz 2 was tested last week.
The Hormuz 2 is capable of hitting floating targets with high accuracy within a range of 300 kilometers (186 miles), Fars said. It provided no additional details.
Meanwhile, the semi-official Tasnim news agency quoted Hajizadeh as saying the Revolutionary Guard had prepared a ballistic missile for civilian purposes but plans to launch it were canceled after a threat by the United States.
Earlier this month, US President Donald Trump imposed new sanctions on entities and individuals who support Iran's ballistic missile program.
Last month, Iranian media reported the Revolutionary Guard launched several sophisticated rockets during military exercises in the country's central desert.