Judge of Israel is one of several names that speak of God as the Judge.
Judge of Israel in Hebrew:
Strong’s Concordance numbers: 8199, 3478
Bible reference: Mic. 5:1
Now gather thyself in troops, O daughter of troops: he hath laid siege against us: they shall smite the judge of Israel with a rod upon the cheek. (Micah 5:1 KJV)
The NIV has “Israel’s Ruler” in this verse because judges were often synonymous with rulers. It is possible that the reference is to a human ruler rather than to God.
There are plenty of similar names for God in which He is described as the Judge: Righteous judge, Judge of (all) the earth, God of justice, our Lawgiver, and Judge of the living and the dead.