The title appears to be referring to a manga in the “reincarnated strong hero / demon king” fantasy niche, but I couldn’t verify a exact official series match from the information available. The closest clearly identified title I found is The God-Slaying Demon King , which follows a former demon king who returns in human form and continues pursuing power.

What I found

  • The God-Slaying Demon King centers on Hiram, a former demon king who is reincarnated 500 years later as a human and starts rebuilding his path forward.
  • The story includes classic fantasy beats like a defeated ruler returning, a dragon encounter, and a journey to challenge what remains of a divine enemy.
  • That said, I did not find a confirmed manga titled exactly “when your wife is the former strongest hero who defeated the demon king.” The phrasing looks more like a fan description or a paraphrased post title than an official series name.

Likely interpretation

If you meant a manga where the protagonist’s wife is a former legendary hero who defeated the demon king, it may be:

  • A fan title
  • A chapter/post caption
  • A light novel or manga adaptation with a longer official Japanese title
  • A social media/forum shorthand for a different series

Trending context

The recent search results around similar fantasy manga show ongoing attention to “former strongest hero” and “demon king” stories, but the specific title you gave does not appear as a clearly established trending manga in the results I found.

Useful next step

The safest identification from the available evidence is The God-Slaying Demon King , but I can’t confirm that it is the exact manga you meant.

TL;DR: I could not verify an exact manga by that name; the closest match is The God-Slaying Demon King.