Glaiza Castro Galura-Rainey (born January 21, 1988), professionally known by her stage name Glaiza de Castro (Tagalog: [ˈglɐjsa dɛ ˈkaːs.tɾo]), is a Filipino actress. Noted for her range in playing a wide range of roles, she is prominent in television and in mainstream, independent and socio-political films. Her performances have earned her accolades including a Luna Award and a Facine Film Festival Award, in addition to a number of nominations from the FAMAS Awards and Gawad Urian Awards.

At age 13, De Castro made her first screen appearance in the series Kasangga (2001). She continued playing minor and supporting roles in the succeeding years and rose to fame after playing Eunice Aragon in the series Stairway to Heaven (2009). The following year, she starred in her first titular role, Grazilda (2010), and played Binayaan in the historical epic series Amaya (2011). She gained further recognition as Heidi Fernandez in the series Temptation of Wife (2012). Her performance earned her a nomination at the Golden Screen TV Awards for Outstanding Supporting Actress in a Drama Series. In 2015, she starred alongside Rhian Ramos in the first lesbian series in the Philippines, The Rich Man's Daughter.

The following year, De Castro starred in one of her biggest roles to date, Pirena, in the series Encantadia (2016). For her role, she won Best Actress at the Gawad Filipino Media People's Choice Awards and Television Actress of the Year at the PEPsters' Choice Awards. In 2018, she starred in another titular role, Contessa, which earned her Best Actress wins at the EdukCircle Awards and Alta Media Icon Awards. In 2022, she starred in the variety series Running Man Philippines with an ensemble cast. In films, she gained critical acclaim for her performances in Still Life (2007), Astig (2009), Liway (2018), and Midnight in a Perfect World (2020). For her work in music, she has earned Gold record for her album Synthesis (2015) and has been named Female Rock Artist of the Year at the PMPC Star Awards for Music.