Social participation is a modifiable determinant for health and well-being among older people; however, social participation is increasingly dependent on technology use. This study investigated social participation in relation to Everyday Technology (ET) use and social deprivation of the living environment among older people with and without dementia in the United Kingdom. Sixty-four older people living with dementia and 64 older people without dementia were interviewed using The Participation in ACTivities and Places OUTside Home Questionnaire and Everyday Technology Use Questionnaire. A mixed-methods approach integrated statistical analyses and content analysis of free-text responses. Small, statistically significant positive associations were found between social participation and ET use outside home, for participants with dementia (Rs = 0.247; p = 0.049) and without dementia (Rs = 0.343; p = 0.006). A small statistically significant positive association was identified between social participation and the index of multiple deprivation in the living environment, among only participants living with dementia (Rs = 0.267, p = 0.033). The content analysis and graphical joint display revealed motivators, considerations that require extra attention, and strategies for managing social participation in relation to ET use. The mixed-methods synthesis revealed a nuanced view of ETs, as both useful in not only planning and preparatory activities but also challenging for social participation.