Nope. Jupiter, Saturn, Uranus and Neptune all have rings (the others' just aren't as impressive as Saturn's).
Because until recently it was thought only Saturn has rings.
No, Saturn is not the only planet with a system of rings. All of the gas giants in our solar system (Jupiter, Saturn, Uranus, and Neptune) have ring systems, although Saturn's rings are the most prominent and well-known.
saturn
Saturn
it is a ring planet
Saturn
Saturn
saturn
That picture represents the planet Saturn. The sphere is the planet itself, while the ring symbolizes its iconic ring system that surrounds it.
Although each of the four gas giants has a ring system, Saturn's ring system is by far the most spectacular, and known as 'THE' ringed planet.
saturn
saturn