This is a chronology of events related to Ashlee Simpson in the year 2004.
"Pieces of Me" begins picking up radio airplay.
- May 20: Ashlee performs "Pieces of Me" at Summer Music Mania.
- May 24: Ashlee performs "Pieces of Me" on The Tonight Show (it airs at about 12:30 AM EST on May 25).
- June 1: Summer Music Mania airs on Fox.
- June 16: The Ashlee Simpson Show debuts on MTV (airs Wednesdays at 10:30 PM).
- June 29: The "Pieces of Me" CD single is released in the U.S.
- July 1: The Ashlee Simpson Show debuts on MTV Canada (airs Thursdays at 9:00 PM eastern time).
- July 16: Ashlee performs "Pieces of Me" on The Late Show with David Letterman.
- July 19: Ashlee performs "Pieces of Me" on Good Morning America (after an interview with Charles Gibson), and she does a live chat with MSN.com. 
- July 20: Autobiography is released in the U.S. Ashlee appears on TRL and does an in-store signing at Virgin Records in New York City.
- July 23: Ashlee does an in-store signing appearance at Tower records in Sherman Oaks, California.
- July 27: Ashlee gives an interview on On Air with Ryan Seacrest and performs "Pieces of Me".
- August 4: The last (eighth) episode of the first season of The Ashlee Simpson Show airs on MTV.
- August 8: Ashlee wins the "Fresh Face" award at the 2004 Teen Choice Awards, and she also receives the "Song of the Summer" award for "Pieces of Me".
- August 29: Ashlee performs "Pieces of Me" during the pre-show for the 2004 MTV Video Music Awards, and during the actual show she presents an award with Tony Hawk for "Best New Artist in a Video."
- Ashlee goes to the U.K. to promote "Pieces of Me" and Autobiography.
- "Shadow" begins its run as the second single in the U.S.
- September 9: Autobiography is certified triple platinum by the RIAA.
- September 10: Ashlee appears on the German version of TRL.
- September 15: Ashlee appears on the UK version of TRL for an interview and also gives an interview on the radio station Capital FM (London).
- September 17: Ashlee sings "Pieces of Me" on Top of the Pops. (U.K.)
- September 18: Ashlee sings "Pieces of Me" on CD:UK.
- September 19: Ashlee sings "Pieces of Me" on Popworld.
- September 20: Ashlee appears on TRL (U.S.); she does not sing "Shadow" as planned due to illness, but still gives an interview.
- September 22: Ashlee sings "Shadow" on Live with Regis and Kelly (after an interview) and The Tonight Show.
- September 25: Ashlee sings "Pieces of Me" on Top of the Pops Saturday. (U.K.)
- September 27: "Pieces of Me" CD single released in the U.K. The first episode of The Ashlee Simpson Show airs in the U.K.
- September 29: Ashlee announces on her website that they have chosen the name "Submission" for her band, since they had received so many submissions of suggestions for the name.
- October 1: The second season of The Ashlee Simpson Show begins taping.
- October 3: Ashlee celebrates her 20th birthday.
- October 4: Autobiography released in the U.K.
- October 24: Ashlee performs "Pieces of Me" on Saturday Night Live (the show began at about 11:35 PM EST on October 23); subsequent performance of "Autobiography" fails due to an error with a backing track she had needed due to illness.
- October 25: Ashlee calls in to TRL to talk about the SNL incident. She performs "Autobiography" at the 2004 Radio Music Awards. The "Pieces of Me" single is certified gold by the RIAA.
- October 26: Ashlee appears on The Today Show to talk with Katie Couric about the SNL incident.
- October 29: It is announced on Ashlee's official website that the third single will be changed from "Autobiography" to "La La".
- October 31: 60 Minutes airs footage from behind the scenes of the SNL show, in which Ashlee is seen having trouble singing during rehearsals due to her illness.
- November 11–12: "La La" video filmed, directed by Joseph Kahn.
- November 14: The Ashlee Simpson Show debuts on MuchMusic in Canada at 4:30 PM eastern time, having been moved up a week from its initially planned debut (November 21). 
- November 18: Ashlee performs "La La" on TRL, following an interview.
- November 22: "La La" video debuts on AOL's "First View" on the Internet.
- November 23: "La La" video debuts on television on MTV's Making the Video.
- December 1: "La La" debuts on the TRL countdown. The Nick & Jessica Christmas special, during which Jessica and Ashlee sing "Little Drummer Boy" together, airs.
- December 6: Ashlee does a show broadcast live over the Internet by AOL Music Live! at the El Rey Theatre in Los Angeles.
- December 8: Ashlee wins the award for Female New Artist of the Year at the 2004 Billboard Music Awards.
- December 17: Simpson performs "La La" on The Tonight Show (the performance airs at about 12:30 AM EST on December 18). Jingle Ball Rock, on which she performed "Pieces of Me" and "La La", airs; the show was taped on December 3.
- December 31: Dick Clark's New Years' Rockin' Eve, in which Simpson hosts the West Coast portion of the show, airs; she also performs "Autobiography", "Pieces of Me", and "La La". It continues into the early hours of January 1.