Gaizka Mendieta Zabala (born March 27, 1974 in Bilbao) is a Spanish football (soccer) midfielder, who currently plays for Middlesbrough of the English Premiership.

Mendieta started his club career with Castellón in 1991 and moved to Valencia a year later. He became one of the most sought-after players in Europe after leading his club to two consecutive Champions League finals in 2000 and 2001. That led to a £29 million transfer to Lazio in 2001, but Mendieta disappointed in Serie A, spending only a year with the Rome club. He was loaned out to Barcelona for the 2002-03 season, and then to Middlesbrough for 2003-04. The latter move was later made permanent. For Spain, Mendieta has been capped 40 times (as of 2005), scoring eight goals. He played for his country at Euro 2000 and the 2002 World Cup.

As a Middlesbrough player, Mendieta was part of the historic team that won the 2004 Carling Cup. After a season of adjusting to the English Premiership, he was expected to make a huge impact in his second season. However, a knee injury ruled him out for most of the campaign.