Zuko’s spouse was never officially confirmed in the main canon, so the honest answer is that we don’t know for sure. The strongest fan theory is that he married Mai , but the series and sequel material never explicitly say who Izumi’s mother is.

What is known

  • In The Legend of Korra , Zuko is shown to have a daughter, Izumi.
  • The story never names Izumi’s mother.
  • Zuko and Mai had an on-and-off romance in Avatar: The Last Airbender , which is why many fans think Mai is the most likely answer.

Best concise answer

  • Officially: unknown.
  • Most likely fan answer: Mai.

TL;DR

Zuko’s marriage was never confirmed on-screen or in canon text, but Mai is the leading theory.