[2] He studied writing at the Royal Melbourne Institute of Technology and screenwriting at the Australian Film, Television and Radio School.

[5] Following this, he wrote for various television programmes in Australia, most notably The Secret Life of Us, Love My Way, Tangle and Puberty Blues.

[3] In 2015, McNamara directed his second feature film, comedy-drama Ashby, starring Mickey Rourke, Sarah Silverman and Emma Roberts.

[7] In 2018, he received critical acclaim for his work in co-writing the historical comedy-drama film The Favourite with Yorgos Lanthimos, starring Emma Stone.

[8] Originally a screenplay by Deborah Davis written 20 years prior to the film's release, Lanthimos and McNamara worked together to complete the final script.