Parkinson's disease (PD) is a multisystem neurodegenerative disorder involving motor and nonmotor symptoms. Cognitive impairment, dysarthria, and dysphagia are common during disease progression and are associated with reduced quality of life, loss of functional independence with activities of daily living, and increased morbidity and mortality. While cognitive impairment, dysarthria, and dysphagia are each well-described in PD, the extent to which cognition influences speech and swallowing function in this population requires further study. This narrative review aims to synthesize current evidence on how cognitive impairment intersects with dysarthria and dysphagia in PD. Relevant literature was identified through targeted database searches and citation tracking, emphasizing correlational and dual-task studies on cognition in relation to speech and swallowing outcomes. Although findings vary across tasks, cognitive domains, and disease severity, the literature collectively suggests that speech and swallowing draw on higher-level cortical processes, particularly attention and executive function, and that cognitive decline and increased cognitive load impact speech and swallowing performance in PD. The burden on the cognitive system is often under-recognized in the context of dysarthria and dysphagia management in PD. Further research that deeply explores the needs of individuals with PD and their care partners across the continuum of cognitive decline is necessary to inform person-centered care, as well as treatment approaches that cooperatively target cognition and speech/swallow function. Finally, future research addressing cognition in the early or even prodromal phase of PD may offer opportunities to increase cognitive reserve and mitigate cognitive decline.