Isaiah 66 is the sixty-sixth and final chapter of the Book of Isaiah in the Hebrew Bible or the Old Testament of the Christian Bible. This book contains the prophecies attributed to the prophet Isaiah, and is one of the Nevi'im. Chapters 56–66 are often referred to as Trito-Isaiah. This chapter contains an oracle delivered after the Second Temple had been built following the Babylonian captivity, and warns against "an unduly materialistic" approach to the worship of God.

The original text was written in Hebrew language. This chapter is divided into 24 verses.

Some early manuscripts containing the text of this chapter in Hebrew are of the Masoretic Text tradition, which includes the Codex Cairensis (895), the Petersburg Codex of the Prophets (916), Aleppo Codex (10th century), Codex Leningradensis (1008).

Fragments containing parts of this chapter were found among the Dead Sea Scrolls (3rd century BC or later):

There is also a translation into Koine Greek known as the Septuagint, made in the last few centuries BCE. Extant ancient manuscripts of the Septuagint version include Codex Vaticanus (B; ${\displaystyle {\mathfrak {G}}}$^B; 4th century), Codex Sinaiticus (S; BHK: ${\displaystyle {\mathfrak {G}}}$^S; 4th century), Codex Alexandrinus (A; ${\displaystyle {\mathfrak {G}}}$^A; 5th century) and Codex Marchalianus (Q; ${\displaystyle {\mathfrak {G}}}$^Q; 6th century).

The parashah sections listed here are based on the Aleppo Codex. Isaiah 66 is a part of the Consolations (Isaiah 40–66). {S}: closed parashah.

This part contains the rebuke to "ecclesiasticism" – 'the spirit that would build human walls around God' (verses 1–2a; cf. 2 Samuel 7:6–7; Acts 7:48–50, 54 and 'breed unreality' (verse 3) and 'intolerance' (verse 5). It is not a protest against the rebuilding of the temple, because it was the command of God (Haggai 1:2–11).

The focus of this section is the end time, where the nation ... brought forth in a moment (cf. 1 Corinthians 15:51–52) with a final divine intervention.