After graduating in 2011, O'Toole's first screen appearance was in a web series titled Sintillate Studios.

[4] He eventually relocated to Sydney where he continued his work in theatre[5] and acted in several short films.

His first appearance in an internationally released film was in The Water Diviner in 2014, alongside Russell Crowe.

[5] That same year, he was cast in the role of Pete in the first three seasons of the TV series Love Child.

[9][10] In 2018, he performed as main actor in the Australian film Nekrotronic, which was nominated for Best Makeup at the 9th AACTA Awards, but otherwise was rather poorly received both by audiences and critics.