Mark Sloan (aka “McSteamy”) first comes to Grey’s Anatomy in Season 2, Episode 18, titled “Yesterday.”

He appears:

  • As a guest star in that Season 2 episode, arriving in Seattle as Derek’s former best friend and a famous plastic surgeon.
  • He then becomes a series regular starting in Season 3 (episode “Sometimes a Fantasy”), when he officially relocates to Seattle Grace to run plastics.

So if you’re watching in order and waiting for him to show up:

  • First appearance (McSteamy entrance): Season 2, Episode 18 – “Yesterday.”
  • Becomes a regular and sticks around: Starting early Season 3.

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