The 2008–09 Copa del Rey was the 107th staging of the Copa del Rey (including two seasons where two rival editions were played).
The competition started on 23 August 2008 and concluded on 13 May 2009 with the final, held at the Mestalla Stadium in Valencia, in which Barcelona lifted the trophy for the record-extending 25th time in their history with a 4–1 victory over Athletic Bilbao, who qualified for the third qualifying round of the 2009–10 UEFA Europa League.
The defending cup holders were Valencia, but they were eliminated in the quarter-finals.
Teams that qualified are the champions of each of the 18 groups (or at least the ones with the highest number of points within their group since reserve teams are excluded): The matches were played on 23, 25, 26, 27 and 28 August 2008.
Team listed first play home in the first leg.