The first book of the Holy Bible is Genesis, and Genesis is the book where Ethiopia is mentioned for the first time in the Bible.

But there are also many other books where Ethiopia is mentioned, as you can see here.

OLD TESTAMENT

Genesis

2:13: And the name of the second river is Gihon: the same is it that compasseth the whole land of Ethiopia.

Numbers

12:1: And Miriam and Aaron spake against Moses because of the Ethiopian woman whom he had married: for he had married an Ethiopian woman.

2 Kings

19:9: And when he heard say of Tirhakah king of Ethiopia, Behold, he is come out to fight against thee: he sent messengers again unto Hezekiah, saying,

2 Chronicles

12:3 With twelve hundred chariots, and threescore thousand horsemen: and the people were without number that came with him out of Egypt; the Lubims, the Sukkiims, and the Ethiopians.

14:9 And there came out against them Zerah the Ethiopian with an host of a thousand thousand, and three hundred chariots; and came unto Mareshah.

14:12 So the LORD smote the Ethiopians before Asa and before Judah; and the Ethiopians fled.

14:13 And Asa and the people that were with him pursued them unto Gerar: and the Ethiopians were overthrown, that they could not recover themselves; for they were destroyed before the LORD, and before his host; and they carried away very much spoil.

16:8 Were not the Ethiopians and the Lubims a huge host, with very many chariots and horsemen? yet, because thou didst rely on the LORD, he delivered them into thine hand.

21:16 Moreover the LORD stirred up against Jehoram the spirit of the Philistines, and of the Arabians, that were near the Ethiopians 

Esther

1:1 Now it came to pass in the days of Ahasuerus, (this is Ahasuerus which reigned, from India even unto Ethiopia, over an hundred and seven and twenty provinces)

8:9 Then were the king's scribes called at that time in the third month, that is, the month Sivan, on the three and twentieth day thereof; and it was written according to all that Mordecai commanded unto the Jews, and to the lieutenants, and the deputies and rulers of the provinces which are from India unto Ethiopia, an hundred twenty and seven provinces, unto every province according to the writing thereof, and unto every people after their language, and to the Jews according to their writing, and according to their language.

Job

28:19The topaz of Ethiopia shall not equal it, neither shall it be valued with pure gold.

Psalms

68:31 Princes shall come out of Egypt; Ethiopia shall soon stretch out her hands unto God.

87:4 I will make mention of Rahab and Babylon to them that know me: behold Philistia, and Tyre, with Ethiopia; this man was born there.

Isaiah

18:1 Woe to the land shadowing with wings, which is beyond the rivers of Ethiopia

20:3 And the LORD said, Like as my servant Isaiah hath walked naked and barefoot three years for a sign and wonder upon Egypt and upon Ethiopia

20:4 So shall the king of Assyria lead away the Egyptians prisoners, and the Ethiopians captives, young and old, naked and barefoot, even with their buttocks uncovered, to the shame of Egypt.

20:5 And they shall be afraid and ashamed of Ethiopia their expectation, and of Egypt their glory.

37:9 And he heard say concerning Tirhakah king of Ethiopia, He is come forth to make war with thee. And when he heard it, he sent messengers to Hezekiah, saying,Isa.43

43:3 For I am the LORD thy God, the Holy One of Israel, thy Saviour: I gave Egypt for thy ransom, Ethiopia and Seba for thee.

45:14 Thus saith the LORD, The labour of Egypt, and merchandise of Ethiopia and of the Sabeans, men of stature, shall come over unto thee, and they shall be thine: they shall come after thee; in chains they shall come over, and they shall fall down unto thee, they shall make supplication unto thee, saying, Surely God is in thee; and there is none else, there is no God.

Jeremiah

13:23 Can the Ethiopian change his skin, or the leopard his spots? then may ye also do good, that are accustomed to do evil.

38:7 Now when Ebed-melech the Ethiopian, one of the eunuchs which was in the king's house, heard that they had put Jeremiah in the dungeon; the king then sitting in the gate of Benjamin;

38:10 Then the king commanded Ebed-melech the Ethiopian saying, Take from hence thirty men with thee, and take up Jeremiah the prophet out of the dungeon, before he die.

38:12 And Ebed-melech the Ethiopian said unto Jeremiah, Put now these old cast clouts and rotten rags under thine armholes under the cords. And Jeremiah did so.

39:16 Go and speak to Ebed-melech the Ethiopian, saying, Thus saith the LORD of hosts, the God of Israel; Behold, I will bring my words upon this city for evil, and not for good; and they shall be accomplished in that day before thee.

46:9 Come up, ye horses; and rage, ye chariots; and let the mighty men come forth; the Ethiopians and the Libyans, that handle the shield; and the Lydians, that handle and bend the bow.

Ezekiel

29:10 Behold, therefore I am against thee, and against thy rivers, and I will make the land of Egypt utterly waste and desolate, from the tower of Syene even unto the border ofEthiopia

30:4 And the sword shall come upon Egypt, and great pain shall be in Ethiopia, when the slain shall fall in Egypt, and they shall take away her multitude, and her foundations shall be broken down.

30:5 Ethiopia, and Libya, and Lydia, and all the mingled people, and Chub, and the men of the land that is in league, shall fall with them by the sword.

30:9 In that day shall messengers go forth from me in ships to make the careless Ethiopians afraid, and great pain shall come upon them, as in the day of Egypt: for, lo, it cometh.

38:5 Persia, Ethiopia, and Libya with them; all of them with shield and helmet

Daniel

11:43 But he shall have power over the treasures of gold and of silver, and over all the precious things of Egypt: and the Libyans and the Ethiopians shall be at his steps.

Amos

9:7 Are ye not as children of the Ethiopians unto me, O children of Israel? saith the LORD. Have not I brought up Israel out of the land of Egypt? and the Philistines from Caphtor, and the Syrians from Kir?

Nahum

3:9 Ethiopia and Egypt were her strength, and it was infinite; Put and Lubim were thy helpers.

Zephaniah

2:12 Ye Ethiopians also, ye shall be slain by my sword.

3:10 From beyond the rivers of Ethiopia my suppliants, even the daughter of my dispersed, shall bring mine offering.

APOCRYPHA

Esdras

3:2 And to all the governors and captains and lieutenants that were under him, from India unto Ethiopia of an hundred twenty and seven provinces.

Judith

1:10 Until ye come beyond Tanis and Memphis, and to all the inhabitants of Egypt, until ye come to the borders of Ethiopia

Esther (the rest)

4:1 The copy of the letters was this: The great king Artexerxeswriteth these things to the princes and governours that are under him from India unto Ethiopia in an hundred and seven and twenty provinces.

7:1 The great king Artexerxes unto the princes and governors of an hundred and seven and twenty provinces from India unto Ethiopia , and unto all our faithful subjects, greeting.

NEW TESTAMENT

Acts

8:27 And he arose and went: and, behold, a man of Ethiopia, an eunuch of great authority under Candace queen of the Ethiopians, who had the charge of all her treasure, and had come to Jerusalem for to worship.