Dragonair evolves into Dragonite starting at level 55 in the mainline Pokémon games.

Quick Scoop: When does Dragonair evolve?

If you’re raising a graceful Dragonair and waiting for that big glow-up, you’ll need to train it until it reaches level 55 ; the moment it levels up past 54, it will evolve into Dragonite (unless you cancel the evolution).

A simple way to remember the line is:

  • Dratini → Dragonair at level 30.
  • Dragonair → Dragonite at level 55.

In Pokémon GO, the evolution is based on candies instead of levels: Dragonair evolves into Dragonite when fed 100 Dratini/Dragonair candies.

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