Ayad Lamdassem (born October 11, 1981 in Sidi Ifni) is a Moroccan-born long distance runner who competes for Spain internationally. He has represented Spain twice in the 10,000 metres at the Summer Olympics (2008 and 2012) as well as the European Athletics Championships (2010, 2012).
Lamdassem has competed at the IAAF World Cross Country Championships on five occasions (once for Morocco and four times for Spain). He was the silver medallist at the European Cross Country Championships in 2010 and 2011. He was also a gold medallist at the 2010 Ibero-American Championships in Athletics.
His personal bests include 13:17.49 minutes for the 5000 metres, 27:45.58 min for the 10,000 m and 61:29 for the half marathon.
He first arrived in Spain in 2002 as part of the Moroccan contingent for the World University Cross Country Championships, which was being held in Santiago de Compostela that year. However, he did not compete and instead deserted the team, using the opportunity to stay on in the country and train with other Moroccans in Valencia. He later moved to Lleida, working with coach Antonio Cánovas, and received citizenship in 2007 after five years of residency.
His first major competition for Spain came the following year in the form of the 2008 Summer Olympics. He ran in the 10,000 m race and finished in 24th place, just behind compatriot Carles Castillejo. He came fourth at the 2008 European Cross Country Championships at the end of the year, helping the Spanish men to the team title. He represented Spain twice at cross country in 2009, coming 30th at the 2009 IAAF World Cross Country Championships and fifth at the 2009 European Cross Country Championships, where Spain retained the team title. He also competed in the 2009 World Championships in Athletics, running in the 10,000 metres, but dropped out mid-race.