Haylie Nichelle Johnson was born to parents Cliff and Nancy Johnson, childhood sweethearts who met in sixth grade. She has an older brother, Chris Johnson, and a younger sister, Ashley Johnson, who is also an actress. When she was three years old, the Johnsons moved from sunny California, to Michigan. Haylie got her start in Michigan, modeling for Loretta Lorion, a local children's clothing store. Both her brother and sister were also in Loretta Lorion ads. Haylie began working steadily in print and commercials (her first was for The Original Cookie Company). Haylie went to school in Michigan for kindergarten and first grade, but then the Johnsons moved back to California to help Haylie and Ashley's rising show business careers.

Haylie did more commercials, and was an extra in Ashley's show Growing Pains (1985), in the episode Daddy Mike (1990). Her big break came in 1991, when she joined the cast of Kids Incorporated (1984). The show was canceled in 1993. A talented singer, Haylie has made one demo tape and plans to pursue a singing career. She would also like to go behind-the-scenes in television and movies, as a writer, director, or producer.