A native of Melbourne, Australia, Amanda Brotchie's first brush with the performing arts came as a busker on the streets of Sydney. During the mid-Eighties, she was a singer with the band Not Drowning, Waving; she also worked with a variety of other acts, and she regularly gave on-stage solo performances. By the early Nineties, Brotchie's focus had turned to acting, including roles on television series such as Chances. As the decade wore on, she also began writing and directing short films. Her success paved the way for Brotchie to direct for television, including episodes of the soap opera Neighbours, while she worked as an assistant to director Michael Rymer on the 2002 supernatural film Queen Of The Damned, which co-starred the Eighth Doctor, Paul McGann. At the same time, Brotchie was working towards a doctoral degree in linguistics at the University of Melbourne.

Having formed High Wire Films with her husband, Adam Zwar, and Nicole Minchin, Brotchie served as an executive producer on programmes such as This Is Littleton and Lowdown; she wrote and directed for both, while also appearing in the latter. Amongst her other credits as both a writer and director during the 2010s were Mr Black and Squinters. In 2022, Brotchie began plying her trade in the United Kingdom, directing two installments of Gentleman Jack. She will also make episodes of Doctor Who for broadcast in 2025, featuring Ncuti Gatwa as the Fifteenth Doctor.