In 2020, Dillon defeated long-time incumbent mayor Rob Chandler for the mayoralty of Barcaldine Regional Council in a close election.[2][3] Upon his victory, Dillon cited his platform of "increased consultation" and "a new approach to water rates" as reasons for his victory.[2] As mayor, he announced plans for a high-voltage transmission line to connect Barcaldine to the national power grid, as part of the Barcaldine Renewable Energy Zone proposal.[4]
After criticising the feasibility of the COVID-19 vaccine rollout in Barcaldine based on the information provided to him in a council meeting, the Office of the Independent Assessor (OIA), an independent statutory body which investigates conduct complaints about Queensland local government councillors, announced an investigation into him.[5] In response Dillon strongly criticised the OIA, labelling the investigation against him "farcical," and called for a parliamentary inquiry into its powers.[6] These sentiments were echoed by Campbell Newman and Jack Dempsey.[7] In February 2022, the complaint was dismissed by the OIA.[8] The OIA blamed the investigation on Dillon having received "incorrect information" from council staff, which Dillon rejected as the OIA having "scapegoated" council employees "for the OIA's administrative incompetence and legal deficiency."[9] In 2023, the Palaszczuk government reduced the scope of the OIA.[10]