On February 1, 2013, CBS renewed
NCIS for this season. The same date Mark Harmon extended his contract on the show with a new "multiyear deal" with CBS. It was announced on July 10, 2013, that
Cote de Pablo, who plays
Ziva David, had chosen not to return for the eleventh season as a regular. She will appear in enough episodes to close out her character's storylines. Glasberg has stated that there will be rotating characters coming to fill Ziva's role. The theme for the season is "unlocking demons", both figurative and literal according to Glasberg. A "pretty interesting adversary" about the theme will be introduced, and "that will carry through the season".
Casting Colin Hanks returned for the premiere episode as
Defense Department investigator Richard Parsons, a character introduced at the end of the tenth season, while
Marina Sirtis returned in the second episode as Mossad Director Orli Elbaz.
Joe Spano also reprised his role as Senior FBI Agent
Tobias C. Fornell in the first two episodes.
Muse Watson (as
Mike Franks) appeared in the fourth episode.
Ralph Waite (as Gibbs' father
Jackson Gibbs) and
Robert Wagner (as Tony's father Anthony DiNozzo, Sr.) are also confirmed to return.
Diane Neal reprises her role CGIS Special Agent Abigail Borin in episode six "Oil & Water". The second episode includes a character named Sarah Porter, played by
Leslie Hope, who is the new
Secretary of the Navy, while
Margo Harshman has been cast in a potentially recurring role as
Timothy McGee's girlfriend, Delilah Fielding. The third episode introduces retiring NCIS Special Agent Vera Strickland (
Roma Maffia) who has known Gibbs for many years. On August 13, 2013, "casting intel" on a new female character named Bishop was published, with filming scheduled to mid-October. Bishop is described as a "twentysomething female[;] bright, educated, athletic, attractive, fresh-faced, focused and somewhat socially awkward. She has a mysterious mixture of analytic brilliance, fierce determination and idealism. She's traveled extensively, but only feels comfortable at home."
Emily Wickersham was cast to play the character, named NSA Analyst Ellie Bishop. Wickersham was promoted to the main cast, two weeks prior of her debut appearance. Her first appearance is in episode nine, "Gut Check".
Scott Bakula was considered for an undisclosed recurring role this season. He was later cast as Dwayne Pride in
NCIS: New Orleans. == Episodes ==