[2] Born in Drexel Hill, Pennsylvania, O'Malley received a double Artium Baccalaureus degree from Kenyon College in Gambier, Ohio, in 1979, graduating magna cum laude and Phi Beta Kappa.

She was in private practice in Cleveland, Ohio, from 1983 to 1991, first at Jones, Day, Reavis and Pogue, until 1985, and then with Porter, Wright, Morris & Arthur, where she became a partner, and had a practice with an emphasis on complex corporate and commercial litigations, including intellectual property, securities fraud, trade secrets, shareholder's rights and large-scale coverage disputes.

[3] On March 10, 2010, President Barack Obama nominated O'Malley for elevation to a seat on the United States Court of Appeals for the Federal Circuit.

[6] Judge O'Malley wrote the second decision in the second appeal in the case overturning the trial court by holding that as a matter of law Google's use of the Java APIs in its Android Operating System was not fair use.

[7] One month after retiring from the bench, in April 2022, O'Malley joined Irell & Manella as of counsel at the firm's newly opened Washington, D.C.