League of Legends officially came out on October 27, 2009 for PC.

Quick Scoop: Release timeline

  • First public reveal: October 7, 2008.
  • Closed beta: around April 2009.
  • Open beta: October 21–26, 2009.
  • Full release (what most people mean by “came out”): October 27, 2009 in North America.

In forum and Reddit discussions, the “birthday” of League is always celebrated on October 27, marking the original 2009 launch date.

TL;DR: If you’re answering “when did League of Legends come out?”, the accepted answer is October 27, 2009.

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