2004
January
February
- February 12 - Matt Sharp and Rivers Cuomo reunite on stage at Cal State Fullerton, playing "Time Song", "Mrs. Young", "Say It Ain't So", and "Undone - The Sweater Song".
March
- March 1 - The BBC publishes its review of the deluxe reissue of the The Blue Album.
- March 23 - Video Capture Device is released on DVD.
- March 23 - The Deluxe Edition of The Blue Album is released.
April
- April 16 - IGN publishes its review of the deluxe reissue of Weezer (The Blue Album).
- April 19 - Rolling Stone publishes its review of the Deluxe Edition of Weezer (The Blue Album).
May
- May 18 - Matt Sharp released his self-titled solo debut, Matt Sharp.
June
- June 11 - Rivers Cuomo records acoustic covers of the 3 "Annie-themed" songs "Invincible" (by Ann Poonkasem), "Annie's Song" (by John Denver) and "Tomorrow" (from the musical "Annie") at the SIR rehearsal studio in Los Angeles, CA. The songs are streamed on Cuomo's MySpace page until they are removed due to copyright issues.
July
- July 2 - Rivers Cuomo records an acoustic version of "The Star Spangled Banner" at the SIR rehearsal studio in Los Angeles, CA. The song is streamed on Cuomo's MySpace page and offered on weezer.com.
August
- August 1 - The book Rivers' Edge: The Weezer Story written by John D. Luerssen is released.
September
- September 14 - Tegan and Sara release their fourth album, So Jealous, featuring contributions from Matt Sharp.