Who were the Midianites in the Bible? Where did they come from?
The Midianites are the descendants of Midian, just as it says in Genesis 25:1-3 where it was written, “Abraham  took another wife, whose name was Keturah. She bore him Zimran, Jokshan, Medan, Midian, Ishbak, and Shuah. Jokshan fathered Sheba and Dedan. The sons of Dedan were Asshurim, Letushim, and Leummim.” Midian had sons too and “The sons of Midian were Ephah, Epher, Hanoch, Abida, and Eldaah. All these were the children of Keturah” (Gen 25:4) who Abraham married after Sarah’s death (Gen 23). All Midianites are descended from Midian and so they are directly descended from Abraham and Keturah, Abraham’s wife. Those who were the sons of Midian (Ephah, Epher, Hanoch, Abida, and Eldaah) are also closely related to the Midianites, being brothers, and are also considered Midianites. The Midianites had a religious and political system close to the Moabites and so they often allied with one another when they faced Israel much later. In biblical times, they lived in the northwestern Arabian Peninsula and with a close proximity to the Promised Land, and later, the nation Israel, the Midianites would prove to be an enemy of a nation who was still in the loins of Abraham.
If you want to know a list of the nations or peoples that would be at opposition to Israel, just take a look at Genesis chapter 36. This chapter contains numerous enemies of God that came from Esau’s descendants, but some of these kept the Midianites subdued for a time, as it says “Hadad the son of Bedad, who defeated Midian in the country of Moab, reigned in his place, the name of his city being Avith” (Gen 36:35). This is frequently how God acts and moves in history. He uses one nation to bring down another; acting as His rod of correction. In the sovereignty of God, He even used the Midianites to save the nation of Israel. This happened when “Midianite traders passed by. And they drew Joseph up and lifted him out of the pit, and sold him to the Ishmaelites for twenty shekels of silver. They took Joseph to Egypt” (Gen 37:28). Joseph’s brother’s evil deeds end up saving the nation of Israel (Gen 50) and by use of Israel’s natural enemy, the Midianites. God can use evil for good for His purposes (Gen 50:20; Rom 8:28). Just look at the cross for the best example.
Balak and Balaam
After Moab had seen “all that Israel had done to the Amorites” (Num 22:2) “Moab was in great dread of the people, because they were many. Moab was overcome with fear of the people of Israel” (Num 22:3) so “Moab said to the elders of Midian, ‘This horde will now lick up all that is around us, as the ox licks up the grass of the field.’” So Balak the son of Zippor, who was king of Moab at that time, sent messengers to Balaam the son of Beor at Pethor, which is near the River in the land of the people of Amaw, to call him, saying, “Behold, a people has come out of Egypt. They cover the face of the earth, and they are dwelling opposite me. Come now, curse this people for me, since they are too mighty for me. Perhaps I shall be able to defeat them and drive them from the land, for I know that he whom you bless is blessed, and he whom you curse is cursed. So the elders of Moab and the elders of Midian departed with the fees for divination in their hand. And they came to Balaam  and gave him Balak’s message” (Num 22:4-7). They wanted Balaam to bring down a curse upon Israel, which of course he couldn’t. All he ended up doing was blessing them. Only when Balaam suggested that Moabite women were sent to the camp could they destroy Israel, from within, by breaking God’s law by sexual immorality and marrying outside of the nation of Israel, with pagan women and so “the Lord spoke to Moses, saying, “Harass the Midianites and strike them down, for they have harassed you with their wiles, with which they beguiled you in the matter of Peor, and in the matter of Cozbi, the daughter of the chief of Midian, their sister, who was killed on the day of the plague on account of Peor” (Num 25:16-17).
God Judges the Midianites
Midian, by choice, had become an enemy of Israel and whoever is an enemy of Israel, is an enemy of God and so “Moses spoke to the people, saying, “Arm men from among you for the war, that they may go against Midian to execute the Lord’s vengeance on Midian” (Num 31:3) and “They warred against Midian, as the Lord commanded Moses, and killed every male” (Num 31:7) so that the Midianites would have no strength anymore. Judgment came to the rest of the Midianites and Balaam too as it says “They killed the kings of Midian with the rest of their slain, Evi, Rekem, Zur, Hur, and Reba, the five kings of Midian. And they also killed Balaam the son of Beor with the sword” (Num 31:8). Now, every male Midianite was dead, every king, and even Balaam who did much harm to Israel by his suggestion to infiltrate the camps with pagan women in the hopes that they would take them for wives. The small remnant left was crushed by God using Gideon’s 300, but the victory was wrought by God and not by men.
You can’t find a Midianite today, I don’t believe. Today, the Midianites are a distant memory and so too will all nations that are opposed to Israel and try to harm her. Just as Christians are the body of Christ and persecuting us is like persecuting Jesus, anyone that is against Israel has God against them. The Midianites might be gone as a nation because it was a judgment from God. Those who are opposed to Israel are opposed to God Himself.
Here is a challenge for you: 20 Genesis Bible Quiz Questions 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), copyright © 2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.