Darby was born and raised in Alaska where her father owned a successful commercial fishing business. She received a Masters in Fine Arts from the American Conservatory Theater in San Francisco. Darby is best known for her role as Abby Whelan on ABC's hit show Scandal, created by Shonda Rhimes. Previously, Darby played prominent recurring roles such as Helen Bishop on period drama, AMC's Mad Men, Shannon Gibbs on CBS's NCIS, and Dr. April Green on CBS's Jericho.