Salem, from the Hebrew word pronounced shaw-lame, meaning peaceful (the well-known Hebrew greeting, pronounced shaw-lome, meaning safe or peace, is derived from the same root word) is found four times in The Bible, twice in the Old Testament (the "Hebrew Scriptures" is actually a much more accurate term for them, since much of what is prophesied in the "Old" Testament is yet to happen in the years just ahead e.g. Daniel's Statue and First And Second Comings In Isaiah) and twice in the New Testament. All four times, it refers to Jerusalem.
It was at Salem that Abraham had his encounter with Melchizedek, the "king of Salem, priest of the Most High God":
"And Melchizedek king of Salem brought out bread and wine; he was priest of God Most High. And he blessed him and said, "Blessed be Abram by God Most High, maker of heaven and earth; and blessed be God Most High, who has delivered your enemies into your hand!" And Abram gave him a tenth of everything." (Genesis 14:18-20 RSV)
"For this Melchizedek, king of Salem, priest of the Most High God, met Abraham returning from the slaughter of the kings and blessed him; and to him Abraham apportioned a tenth part of everything. He is first, by translation of his name, king of righteousness, and then he is also king of Salem, that is, king of peace. He is without father or mother or genealogy, and has neither beginning of days nor end of life, but resembling the Son of God he continues a priest for ever."
"See how great he is! Abraham the patriarch gave him a tithe of the spoils. And those descendants of Levi [see Levites] who receive the priestly office have a commandment in the law to take tithes from the people, that is, from their brethren, though these also are descended from Abraham. But this man who has not their genealogy received tithes from Abraham and blessed him who had the promises. It is beyond dispute that the inferior is blessed by the superior. Here tithes are received by mortal men; there, by one of whom it is testified that he lives. One might even say that Levi himself, who receives tithes, paid tithes through Abraham, for he was still in the loins of his ancestor when Melchizedek met him." (Hebrews 7:1-10 RSV)
Fact Finder: Is Zion in Salem?