Season 4 of Codename: Kids Next Door started on November 19, 2004 in the United States on Cartoon Network. It ended on July 22, 2005.
Season 4 is made up of thirteen episodes. Nine of them are two eleven-minute long episodes. Four of them are full-length, twenty-two minute episodes.
The fourth season showed us more of the global operations, but still kept the main focus on Sector V.
The unproduced episode Operation T.R.E.E.S. was written to be part of this season, but due to copyright by the Dr Seuss estate it was never animated.
This is the only season to have two "art episodes", those being Operation: F.O.O.D.F.I.T.E. and Operation: L.O.V.E..
Episodes[]
| E# | Code | Mission A | Mission B | Original Airdate |
| 40 | 401 | Operation: R.A.B.B.I.T. | Operation: F.L.U.S.H. | November 19, 2004 |
| 41 | 402 | Operation: F.O.O.D.F.I.T.E. | Operation: C.L.U.E.S. | November 26, 2004 |
| 42 | 403 | Operation: N.U.G.G.E.T. | Operation: M.A.C.A.R.R.O.N.I. | December 3, 2004 |
| 43 | 404 | Operation: P.O.O.L. | December 10, 2004 | |
| 44 | 405 | Operation: C.A.K.E.D.-F.O.U.R. | February 21, 2005 | |
| 45 | 406 | Operation: S.I.T.T.E.R. | Operation: S.A.T.U.R.N. | April 29, 2005 |
| 46 | 407 | Operation: C.H.O.C.O.L.A.T.E. | Operation: M.A.T.A.D.O.R. | May 6, 2005 |
| 47 | 408 | Operation: L.U.N.C.H. | Operation: M.U.N.C.H.I.E.S. | May 13, 2005 |
| 48 | 409 | Operation: K.N.O.T. | Operation: C.L.O.S.E.T. | May 20, 2005 |
| 49 | 410 | Operation: S.N.O.W.I.N.G. | May 27, 2005 | |
| 50 | 411 | Operation: M.A.U.R.I.C.E. | July 8, 2005 | |
| 51 | 412 | Operation: L.O.V.E. | Operation: C.O.U.C.H. | July 15, 2005 |
| 52 | 413 | Operation: D.O.D.G.E.B.A.L.L. | Operation: F.E.R.A.L. | July 22, 2005 |
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