Short answer
Yes. Achilles dies before the Trojan Horse episode in the standard Epic Cycle sequence. The Iliad ends with Hector's funeral; Achilles is still alive. The next Cyclic poem, the Aethiopis, brings his death. The horse is told in poems that follow the Aethiopis.
Homer's Odyssey mentions the wooden horse in flashback because Odysseus helped devise it, but that is memory after the war, not a timeline that puts Achilles at the horse.
What the Aethiopis covers
The Aethiopis is a lost Cyclic epic attributed to Arctinus of Miletus. Proclus's Chrestomathy outline, as preserved in modern Epic Cycle handbooks, places it after the Iliad and before the Little Iliad.
In that outline the poem opens after Hector's death with the Amazon Penthesilea aiding Troy; Achilles kills her, then kills Thersites for taunting him, then faces Memnon. Achilles kills Memnon and is himself killed by Paris with Apollo's help. Ajax and Odysseus rescue the body; Thetis and the Muses lament; funeral games follow.
That is the death narrative the Cycle uses. It does not include the horse.
Where the horse sits
The wooden horse belongs to the later sack story. Surviving discussion ties it to the Little Iliad and the Iliupersis (Sack of Troy) traditions in the Epic Cycle, and to Odysseus's role as the plan's architect, which is why the Odyssey can mention the horse without retelling Achilles's death.
Because those poems come after the Aethiopis in the Cycle's chronological lineup, the builders and hiders inside the horse are working in a war Achilles has already left. Any modern retelling that shows Achilles watching the horse roll in is rearranging the Cycle for drama.
For how Achilles dies in more detail, see how did Achilles die. For Patroclus's armor episode earlier in the war, see why Patroclus wears Achilles's armor.
Caveats worth keeping
The Aethiopis itself survives only in scraps; the beat sheet above follows Proclus's summary as modern encyclopedias report it, not a complete ancient text you can quote line by line.
Local cult stories and later Roman poems sometimes reshuffle events. When a source disagrees, ask whether it is following the Epic Cycle order or a free adaptation.
"Before the Trojan Horse" means before the horse stratagem in that Cycle order, not before every story ever told about Troy.
Aethiopis in more detail
Proclus's summary of the Aethiopis (as preserved in the Epic Cycle tradition) places Achilles's final campaigns after the Iliad's funeral games for Patroclus. Penthesileia and the Amazons arrive; Achilles kills her. Memnon, son of Eos, brings Ethiopian allies; Achilles kills him too after a major duel, with divine weighing of fates in the background of the summary.
Achilles's own death follows in the same poem's arc: Paris, with Apollo's help in the usual telling, shoots him. Ajax and Odysseus then compete over his arms. The horse stratagem is not the closing move of the Aethiopis. That matters for the title question: the Cycle parks Achilles's death before the wooden horse adventure that later poems stage.
Because the Aethiopis itself is lost, we depend on Proclus and scattered quotations. Still, the summary order is stable enough in handbooks that "Achilles dies in the Aethiopis phase" is the standard teaching line.
Little Iliad and Iliupersis: where the horse belongs
The Little Iliad covers the post-Achilles phase that leads toward the sack: contests over arms, Philoctetes and the bow, the fetching of Neoptolemus, and the building of the wooden horse among other episodes in the summary tradition. Iliupersis (Sack of Troy) then narrates the horse's entry, the night of destruction, and the fates of Priam's house.
Division of labor is the point for readers. Achilles is already dead before the horse is built and wheeled in. Odysseus and other surviving captains drive that plot. Neoptolemus stands in as Achilles's son during the sack narratives.
Popular films sometimes blur these beats into one continuous "Trojan Horse climax" with Achilles still alive. Cycle chronology says otherwise. If a modern retelling keeps Achilles alive to see the horse, it is adapting, not following Proclus's order.
What the Odyssey remembers
Homer's Odyssey never narrates Achilles's death as a live scene, but it flashes back through other speakers. In the underworld episode of Odyssey 11, Odysseus meets Achilles among the dead, which already assumes the hero has died at Troy before Odysseus's long return. Demodocus and other embedded songs in the poem also treat the sack and related sufferings as past events relative to Odysseus's voyage.
Those flashbacks reinforce the Cycle sequence without giving a forensic wound report. For how Achilles died (heel versus ankle vocabulary, Apollo's role), use a dedicated death page; for whether he died before the horse, the Odyssey's "Achilles is already among the dead while the war's end is sung as past" posture agrees with the Cycle.
Keep primary pointers on Theoi's Achilles page and a Proclus summary text. Treat general encyclopedia pages as orientation only, not the sole factual floor on MythCairn.
Timeline checklist for students
Iliad: Achilles alive; Patroclus dies; Hector dies; Iliad ends before Achilles's death.
Aethiopis (summary): Amazons, Memnon, Achilles slain; arms contest begins.
Little Iliad / Iliupersis (summaries): horse built and used; Troy sacked with Achilles already gone.
Odyssey: Achilles appears among the dead; sack is remembered, not awaited.
Therefore the short answer stays yes: in the standard Epic Cycle order, Achilles dies before the Trojan Horse operation.
Why the question keeps coming back
Modern audiences meet Troy through films and novels that compress years of Cycle material into a few set pieces. Achilles is the emotional center, so writers are tempted to keep him onstage until the horse appears. Classroom chronology pushes the opposite way: his death is an Aethiopis event, and the horse belongs to the sack sequence that follows.
A second confusion is Homeric coverage. Because the Iliad never kills Achilles, readers sometimes assume his death and the horse must share a later "lost Homeric" book. The Cycle poems are the structured answer ancient scholars used for those gaps.
Cite Theoi for the hero dossier, Proclus summaries for poem order, and Perseus/Smith for older handbook orientation.
Arms contest and the path after Achilles
Once Achilles is dead in the Aethiopis outline, the next narrative pressure is not the horse. It is the quarrel over his armor between Ajax and Odysseus, then the chain of recruitment moves that refill the Greek side: Philoctetes and the bow of Heracles, Neoptolemus as Achilles's son, and the building of the wooden horse in the Little Iliad summary tradition.
That order is why classroom timelines put a hard break between "Achilles still alive" material and "sack machinery" material. The horse is a tool of the surviving captains, not a set piece that needs Achilles on stage.
If a modern script collapses armor contest, horse, and sack into one night, it is compressing several Cycle poems. The title question still tracks the older summary order: death first, horse later.
What counts as evidence for the sequence
Primary poetic text for Achilles's death inside the Iliad does not exist; Homer stops earlier. Evidence for the sequence is therefore handbook evidence: Proclus's Chrestomathy summaries, Theoi's assembled testimonia, and older dictionaries that rest on the same Cycle tradition.
That is enough for a yes/no teaching answer. It is not enough to settle every wound detail or every god's exact role in the shot. Keep death-mechanics questions on a dedicated page; keep this page on relative order.
When two popular retellings disagree, ask which Cycle poem they are silently following. Disagreement about color and motive is common; disagreement that puts Achilles alive at the horse against Proclus is adaptation, not Cycle chronology.