Angel Locsin was the original producers' choice to play the title role, but her busy schedule forced her to refuse the offer since she was set to go to London to study fashion design. Angel further reasoned that the series requires the female lead to sing and dance, things she couldn't do.
A video on the auditions held for the MariMar role leaked on YouTube. The actresses featured in the video who auditioned for MariMar include: Bianca King, Nadine Samonte, Katrina Halili, Jennylyn Mercado, Valerie Concepcion, Ryza Cenon, LJ Reyes, Jewel Mische, Karylle, Rhian Ramos, Chesca Garcia, Pauleen Luna, Camille Prats, Nancy Castiglione, and Marian Rivera.
Angel Locsin's refusal to audition for the lead role sparked the feud between the actress and her home studio; she wanted the role offered to her. Angel and her manager Becky Aguila left the network and signed up at rival ABS-CBN.
Bing Loyzaga was earlier tapped to play main villain Angelica; she was given the role of Tia Esperenza.