In 2013, he began starring as a series regular in the television drama series Witches of East End, as Killian Gardiner.[1][2][3][4] Di Tomasso also appeared on Beauty and the Beast, Grimm, CSI: Crime Scene Investigation,[2] Timeless and the Amazon original series Good Girls Revolt. From 2016 through 2018, he joined the series Major Crimes as Detective Wes Nolan.[5] In 2018 he appeared on Chicago Fire series. In 2019 and 2020, he appeared in as Fletcher Myers in The CW reboot series Dynastyin 2020, he was Dario in the Netflix show Ratched in 2021 we will see him in the upcoming show The Republic of Sarah, Y: The Last Man and in the upcoming film French Exit with Michelle Pfeiffer and Lucas Hedges.