The aim of our co-produced, multiple methods study was to explore the language preferences of the autistic community in Northern Ireland and the Republic of Ireland, as well as the preferences of educators supporting autistic learners in this region. A total of 111 participants completed the survey, which included both open- and close-ended questions. Ten of the participants were autistic educators, 35 were autistic non-educators, and 66 were non-autistic educators. Overall, autistic people preferred identity-first terms, such as autistic, neurodivergent, and neurodiverse over person-first terms (e.g., person with autism). Non-autistic educators showed no clear preference for any terms but acknowledged the importance of asking autistic people about their preferences. Based on our findings, it is recommended that educators respect the preferences of the individuals they support. When it is not possible to ask about preferences, educators should opt for identity-first and neuro-affirmative terms, while avoiding person-first terms.