Management of cognitive difficulties is a significant unmet need for individuals with stroke. Incorporating multiple functions, including memory aids and communication tools, smartphones have potential to improve everyday cognitive function and independence in daily activities post-stroke. We aimed to investigate patterns of smartphone use, facilitators and barriers to use, and relationships between smartphone use and daily functioning. Twenty-nine participants with stroke and 29 comparison participants with no history of neurological conditions completed measures of smartphone use, objective and subjective cognitive function, mood and community integration. The majority of participants used smartphones, though the proportion of users was lower in the stroke group (62%) than the comparison group (86%). Older participants were less likely to use smartphones. Using apps that support memory was a main benefit of smartphone use post-stroke. In the stroke group, frequent users of memory apps had significantly fewer motor symptoms (d = 1.20), and higher productivity (d = 0.84). Stroke survivors identified difficulty learning how to use smartphones, but only one participant had assistance with this from a clinician. These results suggest that smartphones have potential as assistive technology post-stroke, however, support in using them is essential, particularly for older individuals with motor dysfunction.