Four planets in our solar system have rings: Jupiter, Saturn, Uranus and Neptune. Saturn's rings are very prominent and are easily observed from the earth with a small telescope.
It wasn't until the Voyager II mission in the 1979 that we were aware of the rings on Jupiter and Neptune.
The rings around Uranus were first identified from earth in 1977 when astronomers observed the planet pass in front of a background star. The starlight blinked out several times before being blocked entirely by the planet itself.