Carlos Diego Loyzaga was born at the Cardinal Santos Hospital in San Juan, Metro Manila. He is the son of Cesar Montano, a multi-awarded actor and director, and former character actress Teresa Loyzaga. He studied at the Marcellis School in Antipolo City for his pre-school education.
In 2000, together with his mother Teresa, they migrated to Australia.He attended the St. Aidans Catholic School in Maroubra, Sydney and the John Forrest School in Perth during his stay in Australia.
At present, he is an incoming junior student in an exclusive school in Metro Manila.