Diane Neal is an American actress. She is best known for portraying New York Assistant District Attorney Casey Novak in the television series Law & Order: Special Victims Unit from 2003 to 2012. She is also known for portraying Coast Guard Investigative Service (CGIS) Special Agent Abigail Borin in the NCIS franchise.

Casey Novak is a fictional character on Law & Order: Special Victims Unit, portrayed by Diane Neal. She is the only female Assistant District Attorney (ADA) to have appeared in five complete seasons in any Law & Order series and the third-longest-running ADA in the entire franchise.