Dissolved inorganic nitrogen (DIN) run-off from sugarcane farms along Australia's Great Barrier Reef (GBR) coast is implicated in poor catchment water quality and putting pressure on reef health. Reducing DIN is the focus of innovative policies to cut pollution and to maximize social benefit across economic sectors. We use Q-methodology to gain insight into discourses present amongst sugarcane sector stakeholders in GBR catchments. Issue statements, which we aligned with concepts from the Theory of Planned Behaviour, were ranked and correlations identified to generate factors that informed our descriptions of discourses. We found four discourse groups we called sector stalwarts, scientific rationalists, economic maximisers, and sector defenders. We also collected respondent demographic data from which we could judge the propensities of respondent groups to identify with different discourses. This information can help industry innovators and policymakers identify the attributes, mindsets, and appropriate language metaphors for engaging stakeholders in reducing catchment pollution.