Which character is Meredith Grey's best friend?

Cristina Yang is Meredith Grey's best friend in Grey's Anatomy. Their friendship begins when they meet as surgical interns and becomes one of the show's defining relationships.

Cristina, played by Sandra Oh, is introduced as an exceptionally ambitious physician with a fierce commitment to cardiothoracic surgery. Meredith and Cristina share dark humor, professional rivalry, emotional honesty, and a habit of supporting each other through disasters at work and in their personal lives. They affectionately become known as the “Twisted Sisters.”

Cristina's phrase “You're my person” captures the importance of their bond. The friendship is deliberately portrayed as central to Meredith's life, sometimes taking priority over romantic relationships. Cristina leaves Seattle at the end of season 10 to run a cardiothoracic research institute in Switzerland, but she remains a major influence on Meredith.

Other characters, including Alex Karev, are also extremely close to Meredith. However, Cristina is the show's canonical best friend and the character most strongly associated with the phrase “my person.”