Background: We conducted a survey to explore the knowledge, attitudes, and practices (KAPs) of hearing healthcare professionals (HHCPs) from several countries (i.e., Australia, India, Netherlands, Malaysia, South Africa, Sri Lanka, Turkey, and the US), specifically regarding the care of clients with comorbid hearing loss and dementia. Methods: A cross-sectional survey was developed and distributed via Qualtrics. Data were summarised and analysed with descriptive statistics, regression analyses, and mixed modelling. Results: In total, N = 385 respondents’ data were analysed, after exclusions. Knowledge of hearing loss and dementia comorbidity was generally high, though respondents were less aware of how to use formal cognitive tests and relevant referral pathways. Further, while attitudes toward HHCPs addressing clients’ cognitive issues were largely positive, a lack of confidence to do so was evident. Meanwhile, practices supporting the cognitive health of HHCP clients were found to be less prevalent, especially the use of formal cognitive tests. Regarding the effect of demographic variables on KAP scores, regression analyses and mixed modelling showed differing effects across countries; these ranged from positive effects of education to effects of sex (i.e., males tending to report higher KAPs than females). Conclusions: These findings help to elucidate the current quality of care for audiological clients affected by dementia. Using these findings, training programs can be developed to empower HHCPs around the world, so that they may deliver optimal healthcare services to clients with comorbid hearing loss and dementia.