She will first be seen playing NSA Analyst Eleanor "Ellie" Bishop in the episode to air Nov. 19.
Her character is described in a news release as "a mysterious mixture of analytic brilliance, fierce determination and idealism who specializes in international threat assessment and global preparation."
"Emily Wickersham's Ellie Bishop is proving to perfectly compliment the NCIS team," executive producer Gary Glasberg said in a statement. "Her energy and enthusiasm is contagious. Great things are planned for Bishop and we couldn't be more thrilled to have her on board."
Wickersham has appeared in the films "Gone," "I Am Number Four" and "Remember Me." Her television credits include "The Sopranos," "The Bridge" and "Gossip Girl."