Yes! There have been groups all along such as Gush Enumin and TNT.
(There are always a few crazies in every country. The two groups mentioned in the answer above have specialized in assassination attempts against Palestinian officials and other sorts of terrorist attacks. However, the Israeli government strives hard to break up Jewish terrorist groups. Just a few days ago, for example, the Israeli police arrested an Jewish extremist who was plotting to blow up an Islamic girl's school in the occupied West Bank.)