The 2009–10 Copa del Rey was the 108th staging of the Copa del Rey (including two seasons where two rival editions were played). The competition began on 22 August 2009 and concluded on 19 May 2010 with the final held at the Camp Nou in Barcelona, in which Sevilla lifted the trophy for the fifth time in their history with a 2–0 victory over Atlético Madrid. The defending cup holders were Barcelona, but they were eliminated by Sevilla in the round of 16. This tournament had quite a number of notable upsets, including Barcelona's early exit in the round of 16, and Real Madrid's shocking 4–0 loss to Alcorcón, which was subsequently nicknamed the "Alcorconazo" and contributed to Real Madrid's early exit in the round of 32.

Qualified teams

The following teams competed in the Copa del Rey 2009–10: 20 teams of 2008–09 La Liga: 21 teams of 2008–09 Segunda División (Sevilla Atlético were excluded for being a reserve team of Sevilla): 24 teams of 2008–09 Segunda División B. Teams that qualified were the top five teams of each of the 4 groups (excluding reserve teams) and the four with the highest number of points out of the remaining non-reserve teams (*): 18 teams of 2008–09 Tercera División. Teams that qualified were 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 were excluded):

First round

The matches were played on 22, 25, 26 and 27 August 2009. Alcorcón, Alcoyano, Atlético Ciudad, Mérida, Ontinyent and Poli Ejido received a bye.

Second round

The matches were played on 1, 2, 3, 9 and 16 September 2009. Recreativo received a bye.

Third round

The matches were played on 7 October 2009. Real Murcia received a bye.

Final phase bracket

Teams that are listed first play at home in the first leg.

Round of 32

The first leg matches were played on 27, 28 and 29 October while the second legs were played on 10, 11 and 12 November 2009.

Round of 16

The first leg matches were played on 5, 6 and 7 January while the second legs were played on 12, 13 and 14 January 2010.

First legs

Second legs

Quarter-finals

First legs

Second legs

Semi-finals

First legs

Second legs

Final

Top goalscorers