He had a breakthrough role as Jason Kennedy, in the first two seasons of Melbourne drama series, Secret Life of Us (2001-2002).

He later had a regular role on the soap opera Home and Away playing Henk van Patten (2007-2008).

Damian de Montemas attended and graduated from Western Australian Academy of Performing Arts (WAAPA).

[1] Damian de Montemas portrayed Jason Kennedy in the first two series of The Secret Life Of Us, and Brian Alexander on Underbelly: A Tale of Two Cities,[1] the latter for which he won the 2009 AFI Award for Best Supporting Actor in a miniseries.

In 2013, de Montemas joined the cast of Neighbours in the guest role of Alek Pocoli.