Bass sued the school, blaming them for not protecting her from a group of mean girls accused of bullying her in classes, in the dorm and on Facebook in 2008.
Attorneys for Miss Porter's School and Bass told the Associated Press in a joint statement that they resolved the 2008 case "with mutual respect" on Dec. 31.
The settlement terms were not disclosed.
The case received national attention from the New York Times and Vanity Fair because it’s a well-known boarding school.
The story goes beyond the allegations of harassment. Bass, distressed by what she was experiencing, cheated on a test, missed some school and was suspended and them expelled, Vanity Fair reported in 2009.
Bass, of Beaufort, South Carolina, was a student government leader and athlete before the alleged harassment.