Ramon Marcelino "Marc" Diaz Abaya (born November 3, 1979), is a Filipino singer-songwriter, actor, model, TV host, and VJ known for his work in alternative rock and television. He began his music career as a member of Shirley Beans before joining the original lineup of the alternative rock band Sandwich in 1998 as vocalist and guitarist, contributing to early albums such as Grip Stand Throw (1998), 4-Track Mind (2001), and Thanks to the Moon’s Gravitational Pull (2003). He left the band in 2005.
He later joined the rock band Kjwan, formed in 2003, and also worked as a video jockey for MTV Philippines. In addition to his music career, he has collaborated with artists such as Gloc-9 on the song "Tsinelas sa Putikan".
As an actor, he appeared in television series including Ligaw na Bulaklak, Your Song (both 2008), and Faithfully (2012), and hosted programs such as It's Showtime segments and Pilipinas Got More Talent. He also acted in films like Dagim (2010), Aswang (2011), and later appeared in series including FPJ’s Ang Probinsyano, The Iron Heart (2022–2023), Roja (2025–2026) and Blood vs Duty (2026).
