The Seattle Mariners have never won the World Series.

Quick Scoop

  • The answer to “when did the Mariners win the World Series?” is: they haven’t won one yet.
  • As of the 2025 season, the Mariners are the only MLB franchise that has never even appeared in a World Series.
  • They came very close in several seasons (notably 1995, 2001, 2022, and a deep 2025 run), but were eliminated in the playoffs each time.

What’s the latest news?

  • In 2025, Seattle made one of its strongest pushes ever, reaching the ALCS and coming within a step of its first World Series berth.
  • That run added fresh fuel to the long-running forum joke/meme that the Mariners’ “first World Series title” is always “next year.”

So if someone on a forum asks, “when did the Mariners win the World Series?”
The accurate, slightly trolling-proof answer is:
They haven’t—yet.

TL;DR: The Seattle Mariners have never won the World Series, and have not even appeared in it as of the latest 2025 season.

Information gathered from public forums or data available on the internet and portrayed here.