The 2005 Grand Prix Hassan II was an Association of Tennis Professionals men's tennis tournament played on outdoor clay courts in Casablanca, Morocco. It was the 21st edition of the tournament and was held from 4 April until 11 April 2005. Sixth-seeded Mariano Puerta won the singles title.
See main article: 2005 Grand Prix Hassan II – Singles. Mariano Puerta defeated Juan Mónaco 6–4, 6–1
See main article: 2005 Grand Prix Hassan II – Doubles. František Čermák / Leoš Friedl defeated Martín García / Luis Horna 6–4, 6–3