The third season of the police procedural drama NCIS was originally broadcast between September 20, 2005, and May 16, 2006, on CBS. The third season opens in the aftermath of "Twilight", with the entire team in shock and Gibbs on a vendetta to seek revenge for Kate's murder. Matters are complicated by the intervention of Gibbs' former lover and new NCIS director Jenny Shepard, and Mossad officer Ziva David.

NCIS is an American military police procedural television series and the first installment within the NCIS media franchise. The series revolves around a fictional team of special agents from the Naval Criminal Investigative Service (NCIS), combining elements of the military drama and police procedural genres with comedy. The concept and characters were initially introduced with two episodes of the CBS series JAG ; as a spin-off from JAG, the series premiered on September 23, 2003, on CBS. To date, it has entered into the 21st full season and has gone into broadcast syndication on the USA Network. Donald P. Bellisario and Don McGill are co-creators and executive producers of the premiere member of the NCIS franchise. As of 2022, NCIS is the third-longest-running scripted, live-action U.S. prime-time TV series currently airing, surpassed only by Law & Order: Special Victims Unit (1999–present) and Law & Order ; it is the seventh-longest-running scripted U.S. prime-time TV series overall.