5 occurrences across the corpus

King James Version

Revelation 1:8

I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty.

Revelation 1:11

Saying, I am Alpha and Omega, the first and the last: and, What thou seest, write in a book, and send it unto the seven churches which are in Asia; unto Ephesus, and unto Smyrna, and unto Pergamos, and unto Thyatira, and unto Sardis, and unto Philadelphia, and unto Laodicea.

Revelation 21:6

And he said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely.

Revelation 22:13

I am Alpha and Omega, the beginning and the end, the first and the last.

NT Apocrypha/Pseudepigrapha

Infancy Gospel of Thomas 6:3

And he told him all the letters from Alpha even to Omega clearly, with much questioning. But Jesus looked upon Zacchaeus the teacher and saith unto hinr: Thou that knowest not the Alpha according to its nature, how canst thou teach others the Beta? thou hypocrite, first, if thou knowest it, teach the Alpha, and then will we believe thee concerning the Beta. Then began he to confound the mouth of the teacher concerning the first letter, and he could not prevail to answer him.