- October 1, 1999
- October 2, 1999
- October 3, 1999
- October 4, 1999
- October 5, 1999
- October 6, 1999
- October 7, 1999
- October 8, 1999
- October 9, 1999
- October 10, 1999 (Original strips were given a new color/shading style from then until the end of the strip.)
- October 11, 1999
- October 12, 1999
- October 13, 1999
- 'October 14, 1999
- October 15, 1999
- October 16, 1999
- October 17, 1999 (The 6th panel in this strip was later reused on the last ever comic strip from February 13, 2000)
- October 18, 1999
- October 19, 1999
- October 20, 1999 (The only strip to reference Red Riding Hood)
- October 21, 1999
- October 22, 1999
- October 23, 1999
- October 24, 1999 (The final football gag, the final appearance of Aaugh!, the final time a character says "Good Grief!", and the last interaction between Charlie Brown and Lucy)
- October 25, 1999 (This is the last time that Peppermint Patty and Snoopy are involved in a storyline.)
- October 26, 1999
- October 27, 1999 (This is the last time that Charlie Brown was involved in a storyline.)
- October 28, 1999
- October 29, 1999 (The final appearance of the French Foreign Legionnaire.)
- October 30, 1999
- October 31, 1999 (The final reference to the Great Pumpkin, the thirty-first and final Zamboni joke, and the last time someone says the word "stupid")
| ← September 1999 | November 1999 → |