María Luisa ("Magüi") Serna Barrera (Spanish pronunciation: [maˈɾi.a ˈlwisa ˈmaɣwi ˈseɾna βaˈreɾa];[a] born 1 March 1979) is a former tennis player from Spain.

She started competing on the ITF Circuit as from 1993, and joined the WTA Tour in 1996.

On 12 January 2004, she reached her career-high singles ranking of world No.

Serna produced an upset by defeating Justine Henin in the 2001 Scottsdale tournament, 7–6, 7–6.

This biographical article relating to Spanish tennis is a stub.