Middleton graduated from the University of Western Australia[1] before joining the Australian Broadcasting Corporation (ABC) in 1970.

[5] In 2008, Middleton left his political role in Canberra to join the Australia Network, presenting Newsline and The World.

[4][5] Middleton took a voluntary redundancy from the ABC following the closure of the Australia Network due to funding cuts[5] signing off on 2 September 2014.

[4] Middleton joined Sky News Australia a month later, beginning on 22 September 2014, as a reporter and foreign correspondent.

[7] Middleton departed Sky News in early 2018 to serve as a senior advisor to former Senator and family friend Tim Storer.