Barbie’s official birthday is March 9, 1959, the day she was unveiled to the toy industry during the New York Toy Fair. She first appeared in her iconic black-and-white striped swimsuit, with a little ponytail. She was initially marketed as a Teenage Fashion Model, available as a blonde or a brunette. Inspired by the German doll Lilli, she was the first children's doll to have full adult features. Creator Ruth Handler defended her decision: "If [a young girl] was going to role play what she would be like when she was 16 or 17, it was a little stupid to play with a doll with a flat chest. So I gave it beautiful breasts."

Ruth hired Fashion Designer Charlotte Johnson to collaborate in the creation of Barbie's original wardrobes, and Jack Ryan, an engineer who worked on missile systems used by the U.S. military, as the head of R&D at Mattel, to bring the first Barbie to life. In 1959, the doll's first year in the market, 300,000 $3 Barbies dolls were sold—a 1959 Barbie in mint condition sold at a 2006 auction for $27,450. Ken became her boyfriend in 1961.