The 44-year-old model and television personality spoke to Entertainment Tonight in an interview Wednesday after Herrington became the third African-American woman to cover the magazine's swimsuit issue.
Banks was the first in 1996.
"It means everything for me, because I didn't dream of being on the cover because I didn't think it was possible. I'd never seen a black model on the cover, so I didn't dream that," she said.
"She paved the way for me," she said of Banks. "This is my idol ... she's so cool and so smart, and I feel like she's always thinking about the next thing. [She is] just so business-oriented, and that's how I want to be. I want to be a businesswoman like her."
Banks, who said she hopes to mentor Herrington, had attended the New York premiere of "Black Panther" with the model Tuesday. She celebrated Herrington's cover in an Instagram post the same day.
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"Do you understand how MAJOR this moment is? @danielle_herrington_ is the 2nd African-American MODEL to grace the cover of #sportsillustratedswimsuit!" the star wrote.
"I was the 1st, but is MY (and YOUR) Model Olympian today! Go go go, Danielle! Make TyTy proud!"
Banks appeared with Argentine model Valeria Mazza on the 1996 cover, and covered the 1997 issue solo.
Singer Beyonce was the second African-American woman to land the cover, appearing in the 2007 edition.
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