It was the second such suit filed against the Palm County School District in the last 10 days, the South Florida Sun Sentinel reported Tuesday.
The band director, Heath Miller, pleaded guilty in March 2012 to four sex charges involving female students. He is serving a 13-year state prison sentence.
The latest suit was filed Monday in U.S. District Court by a woman identified as "Jane Doe" against Miller, the school board, and Ann Wark, principal at the time of Howell L. Watkins Middle School in Palm Beach Gardens where the attacks allegedly occurred.
The lawsuit claims the plaintiff was a 14-year-old eighth grade drum major when Miller molested her five times in the month leading up to April 10, 2009.
A parent identified as K.B. filed a suit Jan. 28 in Palm Beach County Circuit Court on behalf of her daughter, also identified as "K.B.," against the school board.
The complaint alleges the girl was sexually assaulted by Miller April 1-13, 2009, on the Watkins campus.
The school board paid two student victims $150,000 each last fall, spokesman Nat Harrington said.